Qr: switch:"CRY2/CIB1"
Showing 26 - 50 of 609 results
26.
Photoactivatable CRISPR/Cas13d via upconversion nanoparticles for deep tissue RNA engineering and orthopedic therapy.
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Zhao, J
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Zhang, J
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Gao, M
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Miao, Z
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Zhang, Y
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Guo, Y
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Fan, Z
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Tian, J
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Yang, L
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Jiang, N
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Ma, J
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Jiao, J
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Pan, J
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Ma, X
Abstract:
Spatiotemporal control of RNA therapeutics remains a fundamental challenge limiting clinical translation. Here, we develop a photoactivatable CRISPR/Cas13d (paCas13d) system that enables non-invasive, light-controlled RNA manipulation in deep tissues. Through structure-guided engineering, we identify optimal split sites within RfxCas13d and create light-switchable fragments using CRY2PHR/CIBN optogenetic dimerization. To overcome the limited tissue penetration of blue light, we engineer polyethylenimine-functionalized upconversion nanoparticles (UCNPs-PEI) that serve dual roles as gene carriers and photon transducers, converting tissue-penetrating near-infrared (NIR) to blue light. The UCNPs-PEI@paCas13d system achieves precise spatiotemporal control of RNA targeting within bone tissue in vivo. In a murine steroid-associated osteonecrosis model, NIR-activated paCas13d achieves robust TET3 knockdown, disrupting the TET3-5hmC-PTEN axis that drives glucocorticoid-induced osteocyte apoptosis. This targeted intervention prevents bone deterioration, with treated mice showing preserved trabecular architecture, enhanced bone volume, and favorable shifts in bone turnover markers, while maintaining systemic glucocorticoid efficacy. Our platform combines the programmability of CRISPR/Cas13d with non-invasive optical control, offering a versatile approach for treating diseases requiring localized RNA modulation while minimizing systemic effects.
27.
Epigenome regulators imbue a single eukaryotic promoter with diverse gene expression dynamics.
Abstract:
Biological information can be encoded in signaling dynamics, which have been implicated in many physiological processes; yet the diversity of dynamic expression profiles driven by a single gene remains unclear. To explore this, we screen 80 chromatin-associated proteins (CAPs) for their potential to drive diverse dynamic gene expression profiles from the same genome-integrated reporter in yeast. Using locus-specific optogenetic recruitment and live-cell microscopy, we measure dynamic expression profiles within single cells. CAP recruitment elicits a range of responses varying in activation delay, strength, production rate, and noise. We find that promoter activity is characterized by graded, rather than switch-like, transitions. A kinetic model with three promoter states and a positive feedback loop successfully captures the key features of expression driven by each CAP. These results reveal the rich dynamic landscape possible from a single gene, offering insights into native cellular processes and enhancing gene expression control in synthetic biology.
28.
Rationally designed light-inducible RNA-releasing protein for translational regulation and optogenetic control of gene therapies.
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Li, S
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Gao, T
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Wang, Y
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He, Q
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Ma, H
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Ye, H
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Shen, Y
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Wang, Y
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Wang, Y
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Li, X
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Fang, S
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Chen, Q
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Liu, Q
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Sun, G
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Xin, H
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Xue, J
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Liu, S
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Zhu, M
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Xu, W
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Wang, Z
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Shao, J
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Xie, M
Abstract:
In this study, we describe a rationally designed light-inducible RNA-releasing protein (LIRP) capable of inhibiting mRNA translation in the dark while permitting gene expression upon exposure to blue or ambient light. This LIRP-dependent gene switch is compatible with various delivery routes of gene- and cell-based therapy, such as subcutaneous implantation of microencapsulated light-sensitive cells or expression in various light-accessible body sites using single adeno-associated virus (AAV) vectors. To exemplify a gene therapy approach that directly harnesses ambient light as a natural illumination source to induce therapeutic action, we show how intradermal delivery of AAV2 vectors carrying a LIRP-regulated gene switch controlling murine thymic stromal lymphopoietin expression was effective in enabling light-dependent prevention and treatment of diet-induced obesity. To describe another therapeutic scenario, we engineered AAV2 vectors for LIRP-dependent expression of Vascular endothelial growth factor (VEGF) inhibitors for the treatment of retinal neovascular diseases. Upon intravitreal delivery into mice suffering from wet macular degeneration, VEGF inhibitors were constantly produced when animals were exposed to daylight, but therapeutic actions could be flexibly interrupted either by exposure to dark environments or by administration of a selective blue light filter at any point in time. When compared to conventional treatment strategies based on constitutive VEGF inhibition over the course of 3 months, we show that a regulated gene therapy approach through LIRP-dependent optogenetics was advantageous in maintaining a normal retina thickness. This work not only provides a valuable addition to the optogenetic toolbox but also offers a perspective to translate light-dependent gene switches toward therapeutic usage.
29.
Dilating the aging clock with light.
Abstract:
Precise and rapid modeling of aging remains a significant challenge. This review explores the potential of emerging light-based technologies-including direct light exposure, photodynamic therapy (PDT), and optogenetics-as accelerated, mechanistically targeted models for interrogating aging processes. Unlike conventional methods that rely on chronologically aged organisms or non-specific stressors, these light-driven approaches can induce specific hallmark aging phenotypes within days. This offers unprecedented temporal and spatial control, allowing researchers to precisely trigger and define molecular pathways, such as localized oxidative bursts or programmed protein interactions. Such capabilities provide a powerful platform for testing causal hypotheses about aging, especially organ-specific aging. The review also outlines a framework connecting each light modality to aging, including cellular senescence, telomere attrition, proteostasis loss, and epigenetic drift. It discusses a mechanistic matrix linking each light modality to specific molecular targets and age-associated outcomes. Light-based platforms, when combined with genetic and pharmacological tools, are poised to accelerate discovery in aging by enabling high-throughput and organelle-specific perturbation of aging biology. These approaches could ultimately redefine how we experimentally dissect and potentially modulate the aging process either by rapidly recapitulating aging features for study or by revealing leverage points to slow aging.
30.
Optogenetic Tools for Spatiotemporal Interrogation of Cytoskeletal Dynamics.
Abstract:
The cytoskeleton is a dynamic intracellular network that governs cell shape, migration, division, and mechanotransduction. Precise spatiotemporal control of cytoskeletal regulation is essential for understanding how these processes are coordinated in physiology and disease, yet conventional pharmacological and genetic approaches often lack sufficient resolution or reversibility. Optogenetic technologies provide a powerful alternative by enabling light-controlled, noninvasive manipulation of cytoskeletal regulators with high temporal precision and subcellular specificity. This review summarizes recent advances in genetically encoded optogenetic tools for interrogating cytoskeletal dynamics. We discuss core design strategies, including allosteric regulation, light-induced oligomerization, heterodimerization, and dissociation, and highlight representative applications targeting actin filaments, microtubules, and upstream signaling pathways such as Rho family GTPases. We conclude by outlining current limitations and emerging directions, including improved tissue penetration, reduced phototoxicity, and multiplexed optical control, which are expected to further expand the utility of optogenetics in cytoskeleton research.
31.
STIM1 and endoplasmic reticulum-plasma membrane contact sites oscillate independently of calcium-induced calcium release.
Abstract:
Calcium (Ca²+) release from intracellular stores, Ca²+ entry across the plasma membrane and their coordination via store-operated Ca²+ entry (SOCE) are critical for receptor-activated Ca²+ oscillations. However, the precise mechanism of Ca²+ oscillations and whether their control loop resides at the plasma membrane or intracellularly remains unresolved. By examining the dynamics of stromal interaction molecule 1 (STIM1), an endoplasmic reticulum (ER)-localized Ca²+ sensor that activates the Orai1 channel on the plasma membrane for SOCE, in mast cells, we found that a significant proportion of cells exhibited STIM1 oscillations with the same periodicity as Ca²+ oscillations. These cortical oscillations, shared with ER-plasma membrane (ER-PM) contact site proteins, were only detectable using total internal reflection fluorescence microscopy. Notably, STIM1 oscillations could occur independently of Ca²+ oscillations. Simultaneous imaging of cytoplasmic Ca²+ and ER Ca²+ with CEPIA1er revealed that receptor activation does not deplete ER Ca²+, whereas receptor activation without extracellular Ca²+ influx induces cyclic ER Ca²+ depletion. However, under such non-physiological conditions, cyclic ER Ca²+ oscillations lead to sustained STIM1 recruitment, indicating that oscillatory Ca²+ release is neither necessary nor sufficient for STIM1 oscillations. Using optogenetic tools to manipulate ER-PM contact site dynamics, we found that persistent ER-PM contact sites reduced the amplitude of Ca²+ oscillations without alteration of oscillation frequency. Together, these findings suggest an active cortical mechanism governs the rapid dissociation of ER-PM contact sites, thereby controlling amplitude of oscillatory Ca²+ dynamics during receptor-induced Ca²+ oscillations.
32.
Myosin II-driven contractions of supporting cap cells promote sensory adaptation of Drosophila proprioceptors.
Abstract:
Mechanoreceptors can be motile and actively amplify their mechanical input.1,2,3,4 We here found that the responses of mechanoreceptor cells can also be shaped actively by contractile supporting cells. Drosophila larvae monitor body movements with pentascolopidial chordotonal (lch5) organs that are stretched out between cuticular attachment sites.5,6,7,8 These proprioceptive organs contain five stretch-receptor neurons each that receive mechanical stimuli from supporting cap cells. The elastic cap cells are surrounded by extracellular matrix and contain actin cables and non-muscle myosin II motors, suggesting that the cells might be motile.9,10 We show that the supporting cap cells are pre-strained at rest to about twice their relaxed length, and that the force they transmit is modulated by myosin II in the cap cells. Cap cells contracted upon optogenetic activation of myosin II. Cap cell-specific knockdown of the regulatory light chain of myosin II relieved tension and converted the spiking responses of the stretch receptors from phasic to more tonic, impairing adaptation to sustained stimuli. Our findings thus illustrate that mechanoreceptor responses can be actively tailored by contractile neighboring cells.
33.
Advances in mechanistic understanding of light signal transduction derived from plant structural biology.
Abstract:
Light is a pivotal environmental signal regulating diverse plant developmental and physiological processes, including seed germination, hypocotyl elongation, phototropism, metabolite biosynthesis, stress resistance, temperature response, and circadian rhythms. Multiple signal transduction pathways of ultraviolet, blue light, and red/far-red light as well as related protein interaction networks in plants have been identified. Deciphering the mechanisms of light perception and signal transduction is of great significance to crop breeding and optogenetic manipulation. Structural biology has profoundly advanced the studies of light signal transduction by elucidating high-resolution three-dimensional (3D) structures of photoreceptors and their downstream signaling components. These studies uncover the molecular basis underlying perception and transduction of different light signals by plants. This review summarizes key structural findings of plant light signal transduction, highlighting the architectures and molecular functions of photoreceptors and associated signaling factors. We also outline the mechanisms underlying photoreceptor activation, inhibition, and regulatory interactions within light signaling networks and discuss the challenges in this field.
34.
Optogenetic activation of TGFβ signaling drives ligand-free chondrogenesis in hESC-derived MSCs.
Abstract:
Optogenetics holds great potential for diverse biological applications, including fundamental research, tissue engineering, and regenerative medicine, by enabling the precise spatial and temporal control of cellular signaling pathways. Transforming growth factor-beta (TGFβ), a multifunctional cytokine, is a critical regulator of cell proliferation, differentiation, and particularly chondrogenesis. Although TGFβ signaling is necessary for effective chondrogenic differentiation, previous studies have primarily relied on recombinant TGFβ ligand supplementation. In this study, we established an advanced optogenetic platform by knocking-in opto-TGFβ receptors in the AAVS1 locus of human embryonic stem cells (hESCs), enabling precise optogenetic activation of endogenous TGFβ signaling. Blue light illumination specifically activated TGFβ signaling, indicated by enhanced SMAD2 phosphorylation. Employing a three-dimensional pellet culture system, we demonstrated that direct optogenetic activation of TGFβ receptors, without exogenous ligand supplementation, is sufficient for robust chondrogenic differentiation of hESC-derived mesenchymal stem cells. The efficiency of optogenetic differentiation was comparable to conventional recombinant TGFβ protein treatment, evidenced by the expression of chondrogenic markers and deposition of cartilage-specific extracellular matrix components, including aggrecan and type II collagen. Our findings directly confirm the sufficiency and critical role of TGFβ receptor activation itself in chondrogenesis. Furthermore, this optogenetic approach provides a theoretical advantage by enabling noninvasive external modulation of TGFβ signaling post-transplantation, potentially facilitating further maturation and functional integration of transplanted chondrocytes. Thus, our results highlight a promising recombinant-protein-free strategy for use in cartilage tissue engineering and regenerative medicine.
35.
OptoLoop - an optogenetic tool to probe the functional role of genome organization.
Abstract:
The genome folds inside the cell nucleus into hierarchical architectural features, such as chromatin loops and domains. If and how this genome organization influences the regulation of gene expression remains only partially understood. The structure-function relationship of genomes has traditionally been probed by population-wide measurements after mutation of crucial DNA elements or by perturbation of chromatin-associated proteins. To circumvent possible pleiotropic effects of such approaches, we have developed OptoLoop, an optogenetic system that allows direct manipulation of chromatin contacts by light in a controlled fashion. OptoLoop is based on the fusion between a nuclease-dead SpCas9 protein and the light-inducible oligomerizing protein CRY2. We demonstrate that OptoLoop can bring together genomically distant, repetitive DNA loci. As a proof-of-principle application of OptoLoop, we probed the functional role of DNA looping in the regulation of the human telomerase gene TERT. By analyzing the extent of chromatin looping and nascent RNA production at individual alleles, we find evidence for looping-mediated repression of TERT. In sum, OptoLoop represents a novel means for the interrogation of structure-function relationships in the genome.
36.
An orthogonal CRISPR/Cpf1 platform for precise spatiotemporal gene regulation and osteoporotic fracture repair.
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Zhao, J
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Wang, Z
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Lu, L
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Bu, G
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Miao, Z
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Zhang, Y
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Guo, Y
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Yang, Z
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Ma, J
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Jiao, J
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Ma, X
Abstract:
CRISPR-Cas systems enable powerful gene editing and regulation, yet single-modality control often fails to achieve orthogonal, spatiotemporally precise regulation of multiple endogenous genes. We engineered OREC, an orthogonal platform integrating chemogenetic and optogenetic modalities for precise, reversible, multiplex gene control. OREC comprises two components: ORECC regulated by doxycycline (Dox) and ORECo controlled by light. By assembling catalytically dead Cpf1 (dCpf1), gene regulatory elements, and crRNA arrays on single transcripts, OREC enables robust simultaneous manipulation of multiple genes. We demonstrated OREC's therapeutic potential in vitro for osteoblast function modulation and in vivo for osteoporotic fracture repair. OREC effectively activated Bmp2 while inhibiting Dkk1, significantly enhancing bone formation and fracture healing in mouse models. These results establish OREC as a versatile platform for precise multiplex gene regulation, offering significant advancement for CRISPR-based gene therapy applications in complex tissues where coordinated control of multiple therapeutic targets is essential.
37.
Optogenetics for Investigating and Targeting Hallmark Traits of Cancer.
Abstract:
The light-mediated, specific, and precise control of cell functions enabled by optogenetics has become a versatile method for investigating and combatting cancer. An increasing set of optogenetic tools enables tightly controlled regulation of ion flux across biological membranes, gene expression, gene editing, and protein-protein interactions and is being used to interrogate hallmark traits of cancer at the cellular, subcellular, and organismic level. This enables, on the one hand, the identification of critical signaling circuits required for cancer development and progression in vitro and in animal models and can flag potential intervention points for pharmacologic interference. On the other hand, optogenetics can improve the level of control in cell-based therapeutics. The current article provides a review of optogenetic tools and approaches used in the cancer research field and their multiple applications for improving our understanding of signal transduction pathways, modulating immune functions in the tumor microenvironment, facilitating drug screening, or directly attacking cancer cells. Key advantages and achievements of optogenetics in the cancer research field and remaining barriers for clinical applications are discussed.
38.
Novel GαGTP Sensors Reveal Endogenous and Subcellular G Protein Signaling Dynamics.
Abstract:
G protein-coupled receptors (GPCRs) perceive spatially and temporally diverse stimuli and activate G protein heterotrimers comprising α, β, and γ subunits, which broadcast signals through a broad range of effectors at various subcellular compartments. Therefore, understanding endogenous G protein activity dynamics at the subcellular level, thereby recapitulating in vivo signaling paradigms, will facilitate the identification of pathological signaling pathways. However, the lack of sensors for endogenous G proteins has been an obstacle. Here, we demonstrate the engineering of sensors to probe endogenous GαiGTP and GαqGTP. Compared to examining overexpressed and fluorescently tagged Gα, our sensors capture the magnitude and kinetics of endogenous GαGTP dynamics, including their generation, equilibrium signaling, and hydrolysis, with native fidelity. Using the translocation-based GαiGTP sensor, we show that heterotrimer dissociation upon Gi-GPCR activation is Gγ-subtype dependent. Confirming our previous findings, the GαqGTP sensor showed that Gαq expression is low and tightly regulated in most cells. Using optogenetic tools, we demonstrate that our sensors detect GαGTP generation and hydrolysis during asymmetric GPCR-G protein activation, a capability that will be particularly useful in morphologically diverse cells such as neurons. Therefore, our engineered novel GαGTP sensors can be highly beneficial in decoding subcellularly resolved endogenous G protein signaling dynamics.
39.
Notch Signalling Plays a Role in Patterning the Ventral Mesoderm During Early Embryogenesis in Drosophila melanogaster.
Abstract:
Notch signalling is a critical regulator of multiple developmental processes through its ability to control gene expression and thereby influence cell fate specification and cell proliferation through direct cell-cell communication. Although Notch signalling has been implicated in myogenesis during late embryogenesis, its role in early mesoderm development has been largely unexplored. Endocytosis of the Notch ligand Delta and the Notch receptor extracellular domain, a critical step in Notch pathway activation, has been extensively observed in the ventral mesoderm of the early Drosophila embryo, indicating a potential for Notch signalling activity in this early germ layer. Here, we present evidence that genes critical to mesoderm development require and are responsive to Notch signalling activity. Using a novel light-inducible Optogenetic variant of the Notch intracellular domain (OptoNotch), which affords precise spatial and temporal control over ectopic activation of Notch signalling, in combination with high-resolution fluorescent RNA in situ hybridization and qPCR, we identified a set of mesodermal genes whose expression is directly regulated by Notch signalling. We also provide evidence that Notch signalling indirectly regulates the dorsal-ventral patterning program mediated by the Toll signalling pathway through the Dorsal/Twist/Snail gene network. Our findings demonstrate that Notch signalling regulates ventral mesoderm patterning and is critical for establishing the mesoderm-mesectoderm-ectoderm boundary by regulating gene expression patterns and providing negative feedback on the upstream patterning network.
40.
A Non-Mitophagy Activity of BNIP3L/NIX in Amygdala Glutamatergic Neurons is Essential for Contextual Fear Memory Formation.
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Zhang, X
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Mo, X
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Zhou, X
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Liu, X
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Li, G
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Hu, S
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Lu, Y
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Zhu, C
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Feng, J
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Chen, Z
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Hu, W
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Cui, Y
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Chen, Z
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Zhang, X
Abstract:
Mitochondrial quality is crucial for maintaining brain homeostasis. BNIP3L/NIX, a mitophagy receptor, has been linked to neurological disorders, yet its specific function in the brain remains unclear. We found BNIP3L highly expressed in basolateral amygdala (BLA) neurons. Selective deletion of bnip3l in BLA glutamatergic neurons (BLAGLU) impaired contextual fear memory, accompanied by reduced neuronal excitation and mitochondrial respiration. Notably, fear conditioning did not invariably activate mitophagy in BLAGLU neurons. Overexpression of both wild-type and a mitophagy-deficient mutant (BNIP3LΔLIR) in BLAGLU neurons was sufficient to rescue the contextual fear memory deficits in bnip3l-/- mice, suggesting a non-mitophagy role. Instead, we detected a prompt mitochondrial fission in BLAGLU neurons after foot-shock conditioning, an effect abolished by bnip3l deletion. Inhibition of Drp1 with Mdivi-1 disrupted memory formation, whereas optogenetic activation of Drp1 restored neuronal excitation and rescued memory deficits in bnip3l-/- mice. These data indicated an essential role of BNIP3L-mediated mitochondrial fission in modulating contextual fear memory. Mechanistically, BNIP3L and Drp1 competitively interact with AMPK, leading to reduced Drp1 phosphorylation and increased Drp1 accumulation on mitochondria, thereby promoting mitochondrial fission. Taken together, the present study revealed a previously uncharacterized, non-mitophagy-dependent role for BNIP3L in contextual fear memory conditioning.
41.
Redirecting engineered immune cells using G protein-coupled receptors in cancer therapy.
Abstract:
Chimeric antigen receptor (CAR) cellular therapy, particularly CAR-T cells, has revolutionized the treatment of hematologic malignancies. However, these therapies show limited efficacy against solid tumors, in part due to the inefficient trafficking of effector cells to the tumor. This review explores the potential of engineering natural and synthetic G protein-coupled receptors (GPCRs) to overcome this migratory hurdle. Chemokine receptors have been the most used GPCR family in this setting. Engineering effector immune cells to express chemokine receptors that match tumor-derived chemokines has been shown to increase their chemotaxis and to improve antitumor efficacy in preclinical models. In addition to improved migration, chemokine receptor engineering can also have additional benefits, such as remodeling of the tumor microenvironment and metabolic rewiring of engineered cells. However, the effectiveness of this approach is limited by the tumor-specific and heterogeneous chemokine milieu. Emerging strategies make use of synthetic GPCRs and could overcome some of these limitations using chemogenetic and optogenetic approaches. Here, mutated GPCRs binding only to specific and orthogonal ligands or light-sensitive channels are used for cell modulation and trafficking. Equipping cells with these synthetic GPCRs allows for precise and stimulus-controlled immune cell migration. Together, natural and synthetic GPCR engineering form promising approaches to enhance immune cell trafficking, persistence, and efficacy.
42.
Single-cell analysis and control of microbial systems using optogenetics.
Abstract:
Single-cell resolution studies have transformed our understanding of microbial systems, revealing substantial cell-to-cell heterogeneity and complex dynamic behaviors. This review describes recent advances in using optogenetics, where light-sensitive proteins control cellular processes, to investigate microbial behavior at the individual cell level. We discuss studies where optogenetic approaches have enabled high-resolution analysis of properties such as relative cell positioning, subcellular localization, morphology, and gene expression dynamics. In addition, we highlight emerging feedback and event-driven control methods that dynamically modulate cellular states using light signals. By leveraging light's unique capabilities for spatial and temporal manipulation, researchers can now probe cellular characteristics with unprecedented precision. We anticipate significant advances as researchers introduce more sophisticated dynamically patterned light signals for single-cell microbial research.
43.
Dynamic control of Raf-ERK signaling modulates neuronal activity across biological scales.
Abstract:
Neuronal activity robustly engages the extracellular signal-regulated kinase (ERK) signaling pathway through Ca2+-dependent mechanisms; however, whether ERK can acutely and causally modulates ongoing neuronal activity remains unsolved due to complex upstream regulation and diverse subcellular functions. Here, we directly address this question using an optogenetic ERK activator, opto-miniRaf, that enables selective, rapid, graded, and reversible control of ERK signaling. Combining this AAV-compatible system with calcium imaging and electrophysiology, we interrogate ERK functions across biological scales, from cultured neurons, acute brain slices, and the intact brain. Acute optogenetic activation of ERK enhances synchronized network burst activity in cultured rat cortical neurons and increases calcium activity of cortical pyramidal neurons in awake and moving mice following non-invasive light stimulation. Together, these results establish ERK signaling as an acute modulator of neuronal and network activity, positioning opto-miniRaf as a generalizable platform for precise spatiotemporal control of intracellular kinase signaling in complex biological systems.
44.
Pharmaceutical Roots to Mitochondrial Routes: Targeting Neurodegeneration.
Abstract:
Mitochondria besides being the powerhouse of the cell are also involved in performing a multitude of critical cellular functions. Any failure in maintenance of these organelles is implicated in multiple human pathologies, including neurodegenerative disorders. Over the past two decades, significant efforts have been made to investigate the pharmacodynamic propensity of various potential compounds, which could be engaged as efficient therapeutic approach in modulating mitochondrial dynamics during neuronal dysfunctions.
45.
Membrane editing with proximity labeling reveals regulators of lipid homeostasis.
Abstract:
Cellular lipid metabolism is subject to strong homeostatic regulation, but the players involved in and mechanisms underlying these pathways remain largely uncharacterized. Here we develop a 'feeding-fishing' approach coupling membrane editing using optogenetic lipid-modifying enzymes (feeding) with organelle membrane proteomics through proximity labeling (fishing) to elucidate molecular players and pathways involved in the homeostasis of phosphatidic acid (PA), a multifunctional lipid central to glycerolipid metabolism. This approach identified several PA-metabolizing enzymes and lipid transfer proteins enriched in and depleted from PA-fed membranes. Mechanistic analysis revealed that PA homeostasis in the cytosolic leaflets of the plasma membrane and lysosomes is mediated by both local PA metabolism and the action of lipid transfer proteins that carry out interorganelle lipid transport before subsequent metabolism. More broadly, the interfacing of membrane editing to controllably modify membrane lipid composition with organelle membrane proteomics using proximity labeling represents a strategy for revealing mechanisms governing lipid homeostasis.
46.
The multifaceted significance of phosphoinositides in endocytic trafficking.
Abstract:
Phosphoinositides, comprising less than 10% of membrane lipids, function as 'lipid codes' within cellular compartments through seven species formed by myo-inositol headgroup phosphorylation. This review examines their diverse roles in endocytic transport, encompassing endocytosis, endosomal sorting, degradation, and recycling, as well as specialized mechanisms, such as caveolin-mediated endocytosis. The review also investigates the involvement of specific kinases and phosphatases in these processes. Additionally, it discusses the impact of technological advancements, such as fluorescent biosensors, super-resolution microscopy, optogenetics, and synthetic biology, on elucidating phosphoinositide dynamics during endocytic trafficking. Perturbations in phosphoinositide metabolism have been associated with human diseases, including cancer and neurodegenerative disorders. Exploring these pathways may unveil potential therapeutic targets, with subsequent research focusing on their spatiotemporal regulation, tissue-specific metabolism, the synergistic effects of phosphoinositides with other lipids, and the incorporation of systems biology to bridge basic cell biology with translational medicine.
47.
The membrane transition strongly enhances biopolymer condensation through prewetting.
Abstract:
Biopolymers that separate into condensed and dilute phases in solution also prewet membranes when one or more components couple to membrane lipids. Here we demonstrate that this prewetting transition becomes exquisitely sensitive to lipid composition when membranes have compositions near the boundary of liquid-ordered/liquid-disordered phase coexistence in both simulation and in reconstitution when polyelectrolytes are coupled to model membranes. In cells, we use an optogenetic tool to characterize prewetting at both the plasma membrane (PM) and the endoplasmic reticulum (ER) and find that prewetting is potentiated or inhibited by perturbations of membrane composition. Prewetting can also mediate membrane adhesion, with avidity dependent on membrane composition, as demonstrated in cells through the potentiation or inhibition of ER-PM contact sites. The strong correspondence of results in simulation, reconstitution and cells reveals a new role for membrane lipids in regulating the recruitment and assembly of soluble proteins.
48.
The cell biologist's guide to detecting and modulating membrane phospholipids.
Abstract:
Molecular biology has benefited enormously from repurposed tools-many enzymes and antibodies evolved for other functions but are now essential for interrogating biological function by manipulating proteins or nucleic acids. In contrast, lipids have remained technically difficult to visualize or manipulate in cells. This review introduces tools that bring lipid biology into reach for molecular cell biologists, using familiar experimental approaches. We first describe adaptations of immunofluorescence and live-cell imaging of fluorescent molecules to track lipids. Then, we discuss tools for manipulating lipid levels, including pharmacologic inhibitors, synthetic biology platforms for inducible lipid generation or degradation, and optogenetic systems for precise temporal control. While some methods remain technically demanding, most tools are now broadly accessible. Our goal is to offer a practical framework for integrating lipid biology into mainstream cell biology experiments.
49.
Design principles for optogenetic-based targeted protein degradation.
Abstract:
Precise regulation of protein abundance is essential for understanding dynamic cellular processes and for advancing therapeutic development. However, existing approaches lack the spatiotemporal resolution required to these cellular processes. Recent advances in optogenetics have enabled the design of optogenetic targeted protein degradation systems (Opto-TPD) allowing reversible and non-invasive control of protein stability with high spatiotemporal precision. In this review, we systematically summarize the design principles of Opto-TPD tools, including those based on light-oxygen-voltage (LOV)-domain conformational systems, light-inducible dimerization systems, and light-controlled degradation tool expression systems. We further highlight their applications in probing protein function, modulating signaling pathways, and therapeutic translations. By comparing the mechanistic features, performance, and limitations of each platform, we aim to provide a comprehensive resource for guiding future tool optimization. Altogether, these Opto-TPD tools represent a powerful and versatile complement to existing protein manipulation technologies, expanding the toolbox for precise control of protein homeostasis in living systems.
50.
Optogenetic engineering of BAX to control mitochondrial permeabilization and attenuate apoptosis in cells.
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Lee, D
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Bae, H
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Oh, D
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Kim, M
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Kim, JH
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Ahn, J
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Kang, SH
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You, SH
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Kim, DH
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Oh, HJ
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Heo, WD
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Chung, S
Abstract:
Although considerable research has focused on enhancing the apoptotic function of BAX for several decades, inhibition of its functionality remains relatively underexplored, despite intensive BAX activation occurring in various neurodegenerative diseases. Here we present a protein engineering approach to modulate BAX integration into the mitochondrial outer membrane, establishing a tunable strategy for antiapoptosis. Utilizing optogenetic methods that employ cryptochrome 2 and its binding partner cryptochrome-interacting basic helix loop helix 1, we achieved precise spatial control over BAX localization, a critical determinant of its function. Our results demonstrate that the engineered BAX variant is effectively incapacitated in its apoptotic function while also modulating endogenous BAX activity to enhance cellular resistance to apoptosis. These findings not only advance our understanding of BAX regulation but also offer promising prospects for the development of therapeutic strategies against apoptosis-related diseases.
