Vascular endothelium forms a continuous, semipermeable barrier that regulates the transvascular movement of hormones, macromolecules, and other solutes. Here, we describe a novel immediate early gene that is expressed selectively in vascular endothelial cells, verge (vascular early response gene). Verge protein includes an N-terminal region of approximately 70 amino acids with modest homology (approximately 30% identity) to Apolipoprotein L but is otherwise unique. Verge mRNA and protein are induced selectively in the endothelium of adult vasculature by electrical or chemical seizures. Verge expression appears to be responsive to local tissue conditions, because it is induced in the hemisphere ipsilateral to transient focal cerebral ischemia. In contrast to the transient expression in adult, Verge mRNA and protein are constitutively expressed at high levels in the endothelium of developing tissues (particularly heart) in association with angiogenesis. Verge mRNA is induced in cultured endothelial cells by defined growth factors and hypoxia. Verge protein is dramatically increased by cysteine proteinase inhibitors, suggesting rapid turnover, and is localized to focal regions near the periphery of the cells. Endothelial cell lines that stably express Verge form monolayers that show enhanced permeability in response to activation of protein kinase C by phorbol esters. This response is accompanied by reorganization of the actin cytoskeleton and the formation of paracellular gaps. These studies suggest that Verge functions as a dynamic regulator of endothelial cell signaling and vascular function.
The process in which relatively unspecialized cells, e.g. embryonic or regenerative cells, acquire specialized structural and/or functional features that characterize the cells, tissues, or organs of the mature organism or some other relatively stable phase of the organism's life history. Differentiation includes the processes involved in commitment of a cell to a specific fate and its subsequent development to the mature state.
The directed movement of lipids into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore. Lipids are compounds soluble in an organic solvent but not, or sparingly, in an aqueous solvent.
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus indicating lowered oxygen tension. Hypoxia, defined as a decline in O2 levels below normoxic levels of 20.8 - 20.95%, results in metabolic adaptation at both the cellular and organismal level.
Protein involved in angiogenesis, the sprouting or splitting of capillaries from pre-existing vasculature. Angiogenesis plays an important role for example during embryonic development, normal growth of tissues and maintenance of the normal vasculature, wound healing, tumor growth and metastasis.
Protein involved in differentiation, the developmental process of a multicellular organism by which cells become specialized for particular functions. Differentiation requires selective expression of the genome; the fully differentiated state may be preceded by a stage in which the cell is already programmed for differentiation but is not yet expressing the characteristic phenotype determination. Also used for fungal conidiation proteins, and for some bacteria that present specialization of function in cell types, such as Caulobacter crescentus.
Protein involved in development, the process whereby a multicellular organism develops from its early immature forms, e.g., zygote, larva, embryo, into an adult.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.