The cell membrane,a fluid interface composed of self-assembled phospholipid molecules,is a vital component of biological systems that maintains cellular stability and prevents the invasion of foreign toxins.Due to its...The cell membrane,a fluid interface composed of self-assembled phospholipid molecules,is a vital component of biological systems that maintains cellular stability and prevents the invasion of foreign toxins.Due to its inherent fluidity,the cell membrane can undergo bending,shearing,and stretching,making membrane deformation crucial in processes like cell adhesion,migration,phagocytosis,and signal transduction.Within the plasma membrane are highly ordered dynamic structures formed by lipid molecules,known as“lipid rafts,”whose dynamic dissociation and reorganization are prerequisites for membrane deformation.Fluorescent probes have emerged as vital tools for studying these dynamic processes,offering a non-destructive,in situ,and real-time imaging method.By strategically designing these probes,researchers can image not only the microdomains of cell membranes but also explore more complex processes such as membrane fusion and fission.This review systematically summarizes the latest advancements in the application of fluorescent probes for cell membrane imaging.It also discusses the current challenges and provides insights into future research directions.We hope this review inspires further studies on the dynamic processes of complex cell membranes using fluorescent probes,ultimately advancing our understanding of the mechanisms underlying membrane dissociation,reorganization,fusion,and separation,and fostering research and therapeutic development for membrane-associated diseases.展开更多
Regulating the freedom and distribution of H_(2)O molecules has become the decisive factor in enlarging the electrochemical stability window(ESW)of aqueous electrolytes.Compared with the water in a bulk electrolyte,H_...Regulating the freedom and distribution of H_(2)O molecules has become the decisive factor in enlarging the electrochemical stability window(ESW)of aqueous electrolytes.Compared with the water in a bulk electrolyte,H_(2)O molecules at the electrode-electrolyte interface tend to directly split under bias potential.Therefore,the composition and properties of the interfacial microenvironment are the crux for optimizing ESW.Herein,we developed a heterogel electrolyte with wide ESW(4.88 V)and satisfactory ionic conductivity(4.4 mS/cm)inspired by the bicontinuous architecture and surfactant self-assembly behavior in the ionic liquid microemulsion-based template.This electrolyte was capable of expanding the ESW through the dynamic oil/water/electrode interface ternary structure,which enriched the oil phase and assembled the hydrophobic surfactant tails at the interface to prevent H_(2)O molecules from approaching the electrode surface.Moreover,the surfactant Tween 20 and polymer network effectively suppressed the activity of H_(2)O molecules through H-bond interactions,which was beneficial in expanding the operating voltage range and improving the temperature tolerance.The prepared gel electrolyte demonstrated unparalleled adaptability in various aqueous lithium-based energy storage devices.Notably,the lithium-ion capacitor showed an extended operating voltage of 2.2 V and could provide a high power density of 1350.36 W/kg at an energy density of 6 Wh/kg.It maintained normal power output even in the challenging harsh environment,which enabled 11,000 uninterrupted charge-discharge cycles at 0℃.This work focuses on the regulation of the interfacial microdomain and the restriction of the degree of freedom of H_(2)O molecules to boost the ESW of aqueous electrolytes,providing a promising strategy for the advancement of energy storage technologies.展开更多
Morphologically, caveolae and lipid rafts are two different membrane structures. They are often reported to share similar lipid and protein compositions, and are considered to be two subtypes of membrane lipid microdo...Morphologically, caveolae and lipid rafts are two different membrane structures. They are often reported to share similar lipid and protein compositions, and are considered to be two subtypes of membrane lipid microdomains. By modifying sucrose density gradient flotation centrifugation, which is used to isolate lipid microdomains, we were able to separate caveolae and noncaveolar lipid microdomains into two distinct fractions. The caveolar membranes are membrane vesicles of 100-nm diameter, enriched with caveolin-1 and flotillin-1. The noncaveolar lipid microdomains are amorphous membranes and most likely the coalescence of heterogeneous lipid rafts. They are depleted of caveo- lin-1 and are more enriched with cholesterol and sphingolipids than the caveolae. Many membrane proteins, such as insulin-like growth factor-1 receptor （membrane receptor）, aquaporin-1 （membrane transporter）, Thy-1 and N- cadherin （glycosylphosphatidylinositol-anchored membrane protein and membrane glycoprotein）, are specifically as- sociated with noncaveolar lipid microdomains, but not with caveolae. These results indicate that the lipid and protein compositions of caveolae differ from those of noncaveolar lipid microdomains. The difference in their protein compo- sitions implies that these two membrane microdomains may have different cellular functions.展开更多
Here we report the occurrence of garnet porphyroblasts that have overgrown alternating silica-saturated and silica deficient microdomains via different mineral reactions. The samples were collected from ultrahigh-temp...Here we report the occurrence of garnet porphyroblasts that have overgrown alternating silica-saturated and silica deficient microdomains via different mineral reactions. The samples were collected from ultrahigh-temperature(UHT) metapelites in the Highland Complex, Sri Lanka. In some of the metapelites, garnet crystals have cores formed via a dehydration reaction, which had taken place at silicasaturated microdomains and mantle to rim areas formed via a dehydration reaction at silica-deficient microdomains. In contrast, some other garnets in the same rock cores had formed via a dehydration reaction which occurred at silica-deficient microdomains while mantle to rim areas formed via a dehydration reaction at silica-saturated microdomains. Based on the textural observations, we conclude that the studied garnets have grown across different effective bulk compositional microdomains during the prograde evolution. These microdomains could represent heterogeneous compositional layers(paleobedding/laminations) in the precursor sediments or differentiated crenulation cleavages that existed during prograde metamorphism. UHT metamorphism associated with strong ductile deformation, metamorphic differentiation and crystallization of locally produced melt may have obliterated the evidence for such microdomains in the matrix. The lack of significant compositional zoning in garnet probably due to self-diffusion during UHT metamorphism had left mineral inclusions as the sole evidence for earlier microdomains with contrasting chemistry.展开更多
Understanding all facets of membrane microdomains in normal and cancerous cells within the digestive tract is highly important,not only from a clinical point of view,but also in terms of our basic knowledge of cellula...Understanding all facets of membrane microdomains in normal and cancerous cells within the digestive tract is highly important,not only from a clinical point of view,but also in terms of our basic knowledge of cellular transformation.By studying the normal and cancer stem cell-associated molecule CD133 (prominin-1),novel aspects of the organization and dynamics of polarized epithelial cells have been revealed during the last decade.Its association with particular membrane microdomains is highly relevant in these contexts and might also offer new avenues in diagnosis and/or targeting of cancer stem cells.展开更多
Owing to the recent push toward efficient energy storage/conversion devices, fuel cells have become a strong candidate for energy conversion equipments. On the other hand, block copolymer polyelectrolytes are interest...Owing to the recent push toward efficient energy storage/conversion devices, fuel cells have become a strong candidate for energy conversion equipments. On the other hand, block copolymer polyelectrolytes are interesting materials for proton exchange membranes in fuel cells. Thus a considerable attention has been paid to the development of block copolymer polyelectrolyte membranes. In this study, the microdomains in block copolymer polyelectrolytes were controlled by external electric fields to develop high performance membranes with improved proton conductivity. The microdomain alignments in sulfonated polystyrene-b-hydrogenated poly butadiene-b-polystyrene block copolymer electrolyte were monitored by cross-sectional transmission electron microscopy analysis. The proton conductivities of the block copolymer electrolyte membranes were measured before and after exposure to electric field. In addition, the morphological features of the block copolymer electrolyte were observed with small angle x-ray scattering and atomic force microscopy.展开更多
The major brassinosteroid （BR） receptor of Arabidopsis BRASSINOSTEROID INSENSITIVE1 （BRI1） plays fundamental roles in BR signaling, but the molecular mechanisms underlying the effects of BR on BRI1 internalization...The major brassinosteroid （BR） receptor of Arabidopsis BRASSINOSTEROID INSENSITIVE1 （BRI1） plays fundamental roles in BR signaling, but the molecular mechanisms underlying the effects of BR on BRI1 internalization and assembly state remain unclear. Here, we applied variable angle total internal reflection fluorescence microscopy and fluorescence cross-correlation spectroscopy to analyze the dynamics of GFP-tagged BRII. We found that, in response to BR, the degree of co-localization of BRI1-GFP with AtFIotl-mCherry increased, and especially BR stimulated the membrane microdomain-associated pathway of BRI1 internalization. We also verified these observations in endocytosis-defective chc2-1 mutants and the AtFIotl amiRNA 15-5 lines. Furthermore, examination of the phosphorylation status of bril-EMS-suppressor 1 and measurement of BR-responsive gene expression revealed that membrane microdomains affect BR signaling. These results suggest that BR promotes the partitioning of BRI1 into functional membrane microdomains to activate BR signaling.展开更多
Phototropin （phot）-mediated signaling initiated by blue light （BL） plays a critical role in optimizing photosyn- thetic light capture at the plasma membrane （PM） in plants. However, the mechanisms underlying the...Phototropin （phot）-mediated signaling initiated by blue light （BL） plays a critical role in optimizing photosyn- thetic light capture at the plasma membrane （PM） in plants. However, the mechanisms underlying the regu- lation of phot activity at the PM in response to BL remain largely unclear. In this study, by single-particle tracking and stepwise photobleaching analysis of photl-GFP proteins we demonstrated that in the dark photl proteins remain in an inactive state and mostly exist as monomers. Dimerization and the diffusion rate of photl-GFP increased in a dose-dependent manner in response to BL. In contrast, BL did not affect the lateral diffusion of kinase-inactive photlD806N-GFP but did enhance its dimerization, suggesting that photl dimerization is independent of phosphorylation. Forster resonance energy transfer-fluorescence life- time imaging microscopy analysis revealed that the interaction between photl-GFP and a marker of sterol- rich lipid environments, AtRem1.3-mCherry, was enhanced with increased time of BL treatment. However, this BL-dependent interaction was not obvious in plants co-expressing phot1D806N-GFP and AtRem1.3- mCherry, indicating that BL facilitates the translocation of functional photl-GFP into AtRem1.3-1abeled microdomains to activate phot-mediated signaling. Conversely, sterol depletion attenuated photl-GFP dynamics, dimerization, and phosphorylation. Taken together, these results indicate that membrane micro- domains act as organizing platforms essential for the proper function of activated photl at the PM.展开更多
Sphingolipids not only exert structural roles in cellular membranes,but also act as signaling molecules in various physiological and pathological processes.A myriad of studies have shown that abnormal levels of sphing...Sphingolipids not only exert structural roles in cellular membranes,but also act as signaling molecules in various physiological and pathological processes.A myriad of studies have shown that abnormal levels of sphingolipids and their metabolic enzymes are associated with a variety of human diseases.Moreover,blood sphingolipids can also be used as biomarkers for disease diagnosis.This review summarizes the biosynthesis,metabolism,and pathological roles of sphingolipids,with emphasis on the biosynthesis of ceramide,the precursor for the biosynthesis of complex sphingolipids with different fatty acyl chains.The possibility of using sphingolipids for disease prediction,diagnosis,and treatment is also discussed.Targeting endogenous ceramides and complex sphingolipids along with their specific fatty acyl chain to promote future drug development will also be discussed.展开更多
基金supported by the National Nature Science Foundation of China(22107028)State Key Laboratory of Fine Chemicals,Dalian University of Technology(KF2307)+4 种基金Central Guidance Fund for Local Science and Technology Development Project(2024FRD05069)Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0335)ML.wishes to thank the support of the National Natural Science Foundation of China(22308220)Shenzhen Uni-versity Third-Phase Project of Constructing High-Level University(000001032104)the Research Team Culti-vation Program of Shenzhen University(2023QNT005).
文摘The cell membrane,a fluid interface composed of self-assembled phospholipid molecules,is a vital component of biological systems that maintains cellular stability and prevents the invasion of foreign toxins.Due to its inherent fluidity,the cell membrane can undergo bending,shearing,and stretching,making membrane deformation crucial in processes like cell adhesion,migration,phagocytosis,and signal transduction.Within the plasma membrane are highly ordered dynamic structures formed by lipid molecules,known as“lipid rafts,”whose dynamic dissociation and reorganization are prerequisites for membrane deformation.Fluorescent probes have emerged as vital tools for studying these dynamic processes,offering a non-destructive,in situ,and real-time imaging method.By strategically designing these probes,researchers can image not only the microdomains of cell membranes but also explore more complex processes such as membrane fusion and fission.This review systematically summarizes the latest advancements in the application of fluorescent probes for cell membrane imaging.It also discusses the current challenges and provides insights into future research directions.We hope this review inspires further studies on the dynamic processes of complex cell membranes using fluorescent probes,ultimately advancing our understanding of the mechanisms underlying membrane dissociation,reorganization,fusion,and separation,and fostering research and therapeutic development for membrane-associated diseases.
基金supported by the National Natural Science Foundation of China(Grant Nos.22032003 and 22072073)。
文摘Regulating the freedom and distribution of H_(2)O molecules has become the decisive factor in enlarging the electrochemical stability window(ESW)of aqueous electrolytes.Compared with the water in a bulk electrolyte,H_(2)O molecules at the electrode-electrolyte interface tend to directly split under bias potential.Therefore,the composition and properties of the interfacial microenvironment are the crux for optimizing ESW.Herein,we developed a heterogel electrolyte with wide ESW(4.88 V)and satisfactory ionic conductivity(4.4 mS/cm)inspired by the bicontinuous architecture and surfactant self-assembly behavior in the ionic liquid microemulsion-based template.This electrolyte was capable of expanding the ESW through the dynamic oil/water/electrode interface ternary structure,which enriched the oil phase and assembled the hydrophobic surfactant tails at the interface to prevent H_(2)O molecules from approaching the electrode surface.Moreover,the surfactant Tween 20 and polymer network effectively suppressed the activity of H_(2)O molecules through H-bond interactions,which was beneficial in expanding the operating voltage range and improving the temperature tolerance.The prepared gel electrolyte demonstrated unparalleled adaptability in various aqueous lithium-based energy storage devices.Notably,the lithium-ion capacitor showed an extended operating voltage of 2.2 V and could provide a high power density of 1350.36 W/kg at an energy density of 6 Wh/kg.It maintained normal power output even in the challenging harsh environment,which enabled 11,000 uninterrupted charge-discharge cycles at 0℃.This work focuses on the regulation of the interfacial microdomain and the restriction of the degree of freedom of H_(2)O molecules to boost the ESW of aqueous electrolytes,providing a promising strategy for the advancement of energy storage technologies.
文摘Morphologically, caveolae and lipid rafts are two different membrane structures. They are often reported to share similar lipid and protein compositions, and are considered to be two subtypes of membrane lipid microdomains. By modifying sucrose density gradient flotation centrifugation, which is used to isolate lipid microdomains, we were able to separate caveolae and noncaveolar lipid microdomains into two distinct fractions. The caveolar membranes are membrane vesicles of 100-nm diameter, enriched with caveolin-1 and flotillin-1. The noncaveolar lipid microdomains are amorphous membranes and most likely the coalescence of heterogeneous lipid rafts. They are depleted of caveo- lin-1 and are more enriched with cholesterol and sphingolipids than the caveolae. Many membrane proteins, such as insulin-like growth factor-1 receptor （membrane receptor）, aquaporin-1 （membrane transporter）, Thy-1 and N- cadherin （glycosylphosphatidylinositol-anchored membrane protein and membrane glycoprotein）, are specifically as- sociated with noncaveolar lipid microdomains, but not with caveolae. These results indicate that the lipid and protein compositions of caveolae differ from those of noncaveolar lipid microdomains. The difference in their protein compo- sitions implies that these two membrane microdomains may have different cellular functions.
基金the National Research Council(NRC) of Sri Lanka(Grant Nos. 11-180 and 15-089)the Indo-Lanka Joint Grant from the Ministry of Technology and Research,Sri Lanka (MTR/TRD/AGR/3/1/04) for funding this projectsupport by the Stichting Dr Schurmannfonds, Grant Nos. 88/2012, 94/2013 and 101/2014
文摘Here we report the occurrence of garnet porphyroblasts that have overgrown alternating silica-saturated and silica deficient microdomains via different mineral reactions. The samples were collected from ultrahigh-temperature(UHT) metapelites in the Highland Complex, Sri Lanka. In some of the metapelites, garnet crystals have cores formed via a dehydration reaction, which had taken place at silicasaturated microdomains and mantle to rim areas formed via a dehydration reaction at silica-deficient microdomains. In contrast, some other garnets in the same rock cores had formed via a dehydration reaction which occurred at silica-deficient microdomains while mantle to rim areas formed via a dehydration reaction at silica-saturated microdomains. Based on the textural observations, we conclude that the studied garnets have grown across different effective bulk compositional microdomains during the prograde evolution. These microdomains could represent heterogeneous compositional layers(paleobedding/laminations) in the precursor sediments or differentiated crenulation cleavages that existed during prograde metamorphism. UHT metamorphism associated with strong ductile deformation, metamorphic differentiation and crystallization of locally produced melt may have obliterated the evidence for such microdomains in the matrix. The lack of significant compositional zoning in garnet probably due to self-diffusion during UHT metamorphism had left mineral inclusions as the sole evidence for earlier microdomains with contrasting chemistry.
基金Supported by Deutsche Forschungsgemeinschaft(TRR83 No.6SFB655 B3CO298/5-1)
文摘Understanding all facets of membrane microdomains in normal and cancerous cells within the digestive tract is highly important,not only from a clinical point of view,but also in terms of our basic knowledge of cellular transformation.By studying the normal and cancer stem cell-associated molecule CD133 (prominin-1),novel aspects of the organization and dynamics of polarized epithelial cells have been revealed during the last decade.Its association with particular membrane microdomains is highly relevant in these contexts and might also offer new avenues in diagnosis and/or targeting of cancer stem cells.
文摘Owing to the recent push toward efficient energy storage/conversion devices, fuel cells have become a strong candidate for energy conversion equipments. On the other hand, block copolymer polyelectrolytes are interesting materials for proton exchange membranes in fuel cells. Thus a considerable attention has been paid to the development of block copolymer polyelectrolyte membranes. In this study, the microdomains in block copolymer polyelectrolytes were controlled by external electric fields to develop high performance membranes with improved proton conductivity. The microdomain alignments in sulfonated polystyrene-b-hydrogenated poly butadiene-b-polystyrene block copolymer electrolyte were monitored by cross-sectional transmission electron microscopy analysis. The proton conductivities of the block copolymer electrolyte membranes were measured before and after exposure to electric field. In addition, the morphological features of the block copolymer electrolyte were observed with small angle x-ray scattering and atomic force microscopy.
文摘The major brassinosteroid （BR） receptor of Arabidopsis BRASSINOSTEROID INSENSITIVE1 （BRI1） plays fundamental roles in BR signaling, but the molecular mechanisms underlying the effects of BR on BRI1 internalization and assembly state remain unclear. Here, we applied variable angle total internal reflection fluorescence microscopy and fluorescence cross-correlation spectroscopy to analyze the dynamics of GFP-tagged BRII. We found that, in response to BR, the degree of co-localization of BRI1-GFP with AtFIotl-mCherry increased, and especially BR stimulated the membrane microdomain-associated pathway of BRI1 internalization. We also verified these observations in endocytosis-defective chc2-1 mutants and the AtFIotl amiRNA 15-5 lines. Furthermore, examination of the phosphorylation status of bril-EMS-suppressor 1 and measurement of BR-responsive gene expression revealed that membrane microdomains affect BR signaling. These results suggest that BR promotes the partitioning of BRI1 into functional membrane microdomains to activate BR signaling.
基金This work is supported by the National Natural Science Foundation of China （31530084, 31270224） and the Program of Introducing Talents of Discipline to Universities （111 project, B13007）.
文摘Phototropin （phot）-mediated signaling initiated by blue light （BL） plays a critical role in optimizing photosyn- thetic light capture at the plasma membrane （PM） in plants. However, the mechanisms underlying the regu- lation of phot activity at the PM in response to BL remain largely unclear. In this study, by single-particle tracking and stepwise photobleaching analysis of photl-GFP proteins we demonstrated that in the dark photl proteins remain in an inactive state and mostly exist as monomers. Dimerization and the diffusion rate of photl-GFP increased in a dose-dependent manner in response to BL. In contrast, BL did not affect the lateral diffusion of kinase-inactive photlD806N-GFP but did enhance its dimerization, suggesting that photl dimerization is independent of phosphorylation. Forster resonance energy transfer-fluorescence life- time imaging microscopy analysis revealed that the interaction between photl-GFP and a marker of sterol- rich lipid environments, AtRem1.3-mCherry, was enhanced with increased time of BL treatment. However, this BL-dependent interaction was not obvious in plants co-expressing phot1D806N-GFP and AtRem1.3- mCherry, indicating that BL facilitates the translocation of functional photl-GFP into AtRem1.3-1abeled microdomains to activate phot-mediated signaling. Conversely, sterol depletion attenuated photl-GFP dynamics, dimerization, and phosphorylation. Taken together, these results indicate that membrane micro- domains act as organizing platforms essential for the proper function of activated photl at the PM.
基金supported by grants from National Key R&D Program of China(2018YFA0506900,2018YFA0800901)the National Natural Science Foundation of China(NSFC92057202)the Chinese Academy of Sciences(XDB39050900).
文摘Sphingolipids not only exert structural roles in cellular membranes,but also act as signaling molecules in various physiological and pathological processes.A myriad of studies have shown that abnormal levels of sphingolipids and their metabolic enzymes are associated with a variety of human diseases.Moreover,blood sphingolipids can also be used as biomarkers for disease diagnosis.This review summarizes the biosynthesis,metabolism,and pathological roles of sphingolipids,with emphasis on the biosynthesis of ceramide,the precursor for the biosynthesis of complex sphingolipids with different fatty acyl chains.The possibility of using sphingolipids for disease prediction,diagnosis,and treatment is also discussed.Targeting endogenous ceramides and complex sphingolipids along with their specific fatty acyl chain to promote future drug development will also be discussed.
