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Cell Surface (Amsterdam, Netherlands) Dec 2023EXTENSINS (EXTs) are an abundant and yet enigmatic class of cell wall proteins that are found across multicellular plant lineages, from Bryophytes to Angiosperms. They... (Review)
Review
EXTENSINS (EXTs) are an abundant and yet enigmatic class of cell wall proteins that are found across multicellular plant lineages, from Bryophytes to Angiosperms. They have been shown to be integrated within the cell wall matrix, and are proposed to play key roles in the dynamic regulation of cell-wall properties. Consistent with this, EXTs are thought to be important for plant growth and development. However, like many other classes of cell wall proteins, EXTs are biochemically complex, highly diverse, and are encoded by multiple genes, making in-depth functional characterization a challenging undertaking. Here we will provide an overview of current knowledge of the biochemistry and properties of EXTs, and of the tools that have been deployed to study their biological functions in plants.
PubMed: 36659959
DOI: 10.1016/j.tcsw.2023.100094 -
Cell Surface (Amsterdam, Netherlands) Dec 2022Lectins are carbohydrate-binding proteins and are involved in a multitude of biological functions. Lectins at the surface of plant cells often occur as lectin... (Review)
Review
Lectins are carbohydrate-binding proteins and are involved in a multitude of biological functions. Lectins at the surface of plant cells often occur as lectin receptor-like kinases (LecRLK) anchored to the plasma membrane. These LecRLKs are part of the plant's pattern-recognition receptor (PRR) system enabling the plant to perceive threats and respond adequately. Furthermore, plant lectins also occur as secreted proteins, which are associated with stress signalling and defence. The aim of this short review is to provide a general perspective on plant lectins and their role at the cell surface.
PubMed: 36465479
DOI: 10.1016/j.tcsw.2022.100091 -
Cell Surface (Amsterdam, Netherlands) Dec 2018The cell wall is a structure external to the plasma membrane that is essential for the survival of the fungi. This polysaccharidic structure confers resistance to the... (Review)
Review
The cell wall is a structure external to the plasma membrane that is essential for the survival of the fungi. This polysaccharidic structure confers resistance to the cell internal turgor pressure and protection against mechanical injury. The fungal wall is also responsible for the shape of these organisms due to different structural polysaccharides, such as β-(1,3)-glucan, which form fibers and confer rigidity to the cell wall. These polysaccharides are not present in animal cells and therefore they constitute excellent targets for antifungal chemotherapies. Cell wall damage leads to the activation of MAPK signaling pathways, which respond to the damage by activating the repair of the wall and the maintenance of the cell integrity. Fission yeast is a model organism for the study morphogenesis, cell wall, and how different inputs might regulate this structure. We present here a short overview of the fission yeast wall composition and provide information about the main biosynthetic activities that assemble this cell wall. Additionally, we comment the recent advances in the knowledge of the cell wall functions and discuss the role of the cell integrity MAPK signaling pathway in the regulation of fission yeast wall.
PubMed: 32743131
DOI: 10.1016/j.tcsw.2018.10.001 -
Bioarchitecture 2015The neural cell adhesion molecule (NCAM) regulates differentiation and functioning of neurons by accumulating at the cell surface where it mediates the interactions of... (Review)
Review
The neural cell adhesion molecule (NCAM) regulates differentiation and functioning of neurons by accumulating at the cell surface where it mediates the interactions of neurons with the extracellular environment. NCAM also induces a number of intracellular signaling cascades, which coordinate interactions at the cell surface with intracellular processes including changes in gene expression, transport and cytoskeleton remodeling. Since NCAM functions at the cell surface, its transport and delivery to the cell surface play a critical role. Here, we review recent advances in our understanding of the molecular mechanisms of the intracellular transport and cell surface delivery of NCAM. We also discuss the data suggesting a possibility of cross talk between activation of NCAM at the cell surface and the intracellular transport and cell surface delivery of NCAM.
Topics: Animals; Humans; Neural Cell Adhesion Molecules; Neurons; Protein Transport; Receptor Cross-Talk
PubMed: 26605672
DOI: 10.1080/19490992.2015.1118194 -
Cell Surface (Amsterdam, Netherlands) Dec 2022•The outer surfaces of fungi and bacteria are highly dynamic, flexible, regulated and adaptable structures.•The term "cell wall" is conceptually limiting and... (Review)
Review
•The outer surfaces of fungi and bacteria are highly dynamic, flexible, regulated and adaptable structures.•The term "cell wall" is conceptually limiting and insufficient to adequately describe the outer surface of bacteria and fungi.•The Greek term plégma or in Latin word "reticulum" better capture the nature of the cell wall.
PubMed: 36405351
DOI: 10.1016/j.tcsw.2022.100087 -
Cell Surface (Amsterdam, Netherlands) Dec 2020
PubMed: 32743149
DOI: 10.1016/j.tcsw.2020.100037 -
International Journal of Molecular... May 2022Plasminogen (Plg) activation to the serine protease plasmin (Pla) plays a key role in regulating wound healing and fibrotic responses, particularly when bound to cell...
Plasminogen (Plg) activation to the serine protease plasmin (Pla) plays a key role in regulating wound healing and fibrotic responses, particularly when bound to cell surface receptors. Our previous work suggested that mesothelial cells bind Plg at the cell surface, though no Plg receptors were described for these cells. Since mesothelial cells contribute to injury responses, including cellular differentiation to a mesenchymal-like phenotype and extracellular matrix remodeling, we hypothesized that Plg binding would promote these responses. Here, we confirm that Plg binds to both pleural and peritoneal mesothelial cells via the lysine-binding domain present in Plg, and we demonstrate the presence of three Plg receptors on the mesothelial cell surface: α-Enolase, Annexin A2, and Plg-R. We further show that bound-Plg is activated to Pla on the cell surface and that activation is blocked by an inhibitor of urokinase plasminogen activator or by the presence of animal-derived FBS. Lastly, we demonstrate that Plg promotes mesothelial cell invasion through a type I collagen matrix but does not promote cellular differentiation or proliferation. These data demonstrate for the first time that mesothelial cells bind and activate Plg at the cell surface and that active Pla is involved in mesothelial cell invasion without cell differentiation.
Topics: Animals; Collagen; Fibrinolysin; Plasminogen; Receptors, Cell Surface; Urokinase-Type Plasminogen Activator
PubMed: 35682663
DOI: 10.3390/ijms23115984 -
Cell Surface (Amsterdam, Netherlands) Dec 2021The bacterial cell wall contains numerous surface-exposed proteins, which are covalently anchored and assembled by a sortase family of transpeptidase enzymes. The... (Review)
Review
The bacterial cell wall contains numerous surface-exposed proteins, which are covalently anchored and assembled by a sortase family of transpeptidase enzymes. The sortase are cysteine transpeptidases that catalyzes the covalent attachment of surface protein to the cell wall peptidoglycan. Among the reported six classes of sortases, each distinct class of sortase plays a unique biological role in anchoring a variety of surface proteins to the peptidoglycan of both pathogenic and non-pathogenic Gram-positive bacteria. Sortases not only exhibit virulence and pathogenesis properties to host cells, but also possess a significant role in gut retention and immunomodulation in probiotic microbes. The two main distinct functions are to attach proteins directly to the cell wall or assemble pili on the microbial surface. This review provides a compendium of the distribution of different classes of sortases present in both pathogenic and non-pathogenic Gram-positive bacteria and also the noteworthy role played by them in bacterial cell wall assembly which enables each microbe to effectively interact with its environment.
PubMed: 34195501
DOI: 10.1016/j.tcsw.2021.100055 -
Cell Surface (Amsterdam, Netherlands) Dec 2022Pathogenic fungi hide from their hosts by camouflage, obscuring immunogenic cell wall components such as beta-glucan with innocuous coverings such as mannoproteins and...
Pathogenic fungi hide from their hosts by camouflage, obscuring immunogenic cell wall components such as beta-glucan with innocuous coverings such as mannoproteins and alpha-glucan that are less readily recognised by the host. Attempts to understand how such processes are regulated have met with varying success. Typically studies focus on understanding the transcriptional response of fungi to either their reservoir environment or the host. However, such approaches do not fully address this research question, due to the layers of post-transcriptional and post-translational regulation that occur within a cell. Although in animals the impact of post-transcriptional and post-translational regulation has been well characterised, our knowledge of these processes in the fungal kingdom is more limited. Mutations in RNA-binding proteins, like Ssd1 and Slr1, affect cell wall composition and fungal virulence indicating that post-transcriptional regulation plays a key role in these processes. Here, we review the current state of knowledge of fungal post-transcriptional regulation, and link this to potential mechanisms of immune evasion by drawing on studies from model yeast and plant pathogenic fungi. We highlight several RNA-binding proteins that regulate cell wall synthesis and could be involved in local translation of cell wall components. Expanding our knowledge on post-transcriptional regulation in human fungal pathogens is essential to fully comprehend fungal virulence strategies and for the design of novel antifungal therapies.
PubMed: 35097244
DOI: 10.1016/j.tcsw.2022.100074 -
Nature Apr 2014Fertilization occurs when sperm and egg recognize each other and fuse to form a new, genetically distinct organism. The molecular basis of sperm-egg recognition is...
Fertilization occurs when sperm and egg recognize each other and fuse to form a new, genetically distinct organism. The molecular basis of sperm-egg recognition is unknown, but is likely to require interactions between receptor proteins displayed on their surface. Izumo1 is an essential sperm cell-surface protein, but its receptor on the egg has not been described. Here we identify folate receptor 4 (Folr4) as the receptor for Izumo1 on the mouse egg, and propose to rename it Juno. We show that the Izumo1-Juno interaction is conserved within several mammalian species, including humans. Female mice lacking Juno are infertile and Juno-deficient eggs do not fuse with normal sperm. Rapid shedding of Juno from the oolemma after fertilization suggests a mechanism for the membrane block to polyspermy, ensuring eggs normally fuse with just a single sperm. Our discovery of an essential receptor pair at the nexus of conception provides opportunities for the rational development of new fertility treatments and contraceptives.
Topics: Animals; Conserved Sequence; Evolution, Molecular; Female; Fertility; Fertilization; Genes, Essential; Glycosylphosphatidylinositols; Humans; Immunoglobulins; Infertility, Female; Male; Mammals; Membrane Proteins; Mice; Oocytes; Ovum; Parthenogenesis; Receptors, Cell Surface; Sperm Injections, Intracytoplasmic; Spermatozoa; Time Factors
PubMed: 24739963
DOI: 10.1038/nature13203