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collagen alpha-1(VIII) chain; endothelial collagen; contains: vastatin (COL8A1, C3orf7)

Function: - macromolecular component of the subendothelium - major component of the Descemet's membrane (basement membrane corneal endothelium) - also component of the endothelium of blood vessels - necessary for migration & proliferation of vascular smooth muscle cells - Pro at the third position of the tripeptide repeating unit (G-X-Y) are hydroxylated in some or all of the chains - proteolytically cleaved by neutrophil elastase, in vitro - proteolytic processing produces the C-terminal NC1 domain fragment, vastatin - homotrimers, or heterotrimers in association with COL8A2 - four homotrimers can form a tetrhedron stabilized by central interacting C-terminal NC1 trimers Structure: - contains 1 C1q domain - four consecutive Gly-Pro-Pro triplets are present at the C-terminus of the triple-helical region - these may provide the high thermal stability of this region Compartment: - secreted, extracellular space - extracellularmatrix, basement membrane Expression: - expressed primarily in subendothelium of large blood vessels - also expressed in arterioles & venules in muscle, heart, kidney, spleen, umbilical cord, liver & lung - also found in connective tissue layers around hair follicles, around nerve bundles in muscle, in the dura of the optic nerve, in cornea & sclera, & in the perichondrium of cartilage - tn the kidney, expressed in mesangial cells, glomerular endothelial cells, & tubular epithelial cells - also expressed in mast cells, & in astrocytes during the repair process - expressed in Descemet's membrane - specifically expressed in peritoneal fibroblasts & mesothelial cells Pathology: - possible role in atherogenesis via effect on proliferation of vascular smooth muscle cells - up-regulated during vascular injury, in atherosclerosis & in diabetes

Specific

vastatin

General

collagen subunit

Properties

SIZE: entity length = 744 aa MW = 73 kD MOTIF: signal sequence {1-27} Nonhelical region (NC2) {29-117} Triple-helical region (COL1) {118-571} Nonhelical region (NC1) {572-744} MOTIF: C1q {611-744}

Database Correlations

OMIM 120251 UniProt P27658 PFAM correlations Entrez Gene 1295 Kegg hsa:1295

References

  1. UniProt :accession P27658
  2. Molecular Cell Biology (2nd ed) Darnell J; Lodish H & Baltimore D (eds), Scientific American Books, WH Freeman, NY 1990, pg 906
  3. Entrez Gene :accession 1295

Component-of

collagen type-8 (endothelial collagen)