Collagen type VIII

Collagens Type VIII and X form hexagonal networks. They are shorter than collagen IV and the networks that they form are more regular. However, no detailed three-dimensional (3D) description exists of the networks that they form in terms of crystallographic symmetry and stoichiometry. 

Sutmuller, M., Bruijin, J. A., and de Heer, E. (1997). Collagens Type VIII and X two non-fibrillar, short chain collagens. Structure homologies, functions and involvement in pathology. Histol. Histopathol. 12, 557-566. 

Hexagonal network forming collagen Type VIII, X... 

The NCI domain of type VIII collagen is important for trimerization. ACRP30/adiponectin, a member of the complement Clq family of proteins,and the type X collagen NCI domain have similar structures as the NCI domain of type VIII collagen however, the type Vlll collagen NCI trimer lacks the buried calcium cluster found in the type X collagen NCI trimer. The crystal structure of this domain has similarity to the TNF (tumor necrosis factor) family of proteins (PDB accession number 1091). ... 

Network-forming collagens (types IV, VIII, andX)... 

Type VIII collagen is composed of highly conserved al(VIII) and a2(VIII) chains, which contain a short collagenous domain of454 residues flanked by an N-terminal NC domain of 117 residues and a C-terminal NC domain of 173 residues." The chains assemble into two distinct homotrimers that assemble into hexagonal lattices. ° The crystal structure of the al C-terminal NC homotrimerization domain was determined (see Section 5.16.6.5). 

Type X collagen has a single al chain, which contains a short collagenous domain of 460 residues, flanked by an N-terminal NC domain of 37 residues and C-terminal NC domain of 161 residues." Its protomer is a homotrimer. The C-terminal NC domain is responsible for trimerization and multimer formation, which is based on experiments with recombinant domains." The crystal structure of type X collagen trimerization domain is similar to that of type VIII collagen (see also Section 5.16.6.5). 

Figure 22 Structures of type VIII (a) and X (b) collagens NCI single chains (PDB accession numbers 1091 and 1GR3, respectively) viewed perpendicular to the three-fold axis. The figure was generated using the UCSF Chimera package.

The organization of type VIII collagen that has been studied most closely is that in Descemet s membrane, where it forms a hexagonal lattice... 

Hou, G., Mulholland, D., Gronska, M. A., and Bendeck, M. P. (2000). Type VIII collagen stimulates smooth muscle cell migration and matrix metalloproteinase synthesis after arterial injury. Am. J. Pathol. 156, 467 76. 

Illidge, C., Kielty, C., and Shutdeworth, A. (2001). Type VIII collagen Heterotrimeric chain association. Int. J. Biochem. C. Biol. 33, 521-529. 

At least nine of the collagens - types I, HI, IV, V, VI, VIII, XII, XIII, and XIV - have been found in the vessel walP. The ratio of the various collagen molecules in a normal and in an arteriosclerotic vessel wall is different . The fibril-forming collagens type I,... 

The sclera is composed of collagen fibrils embedded in a glycosaminoglycan (GAG) matrix. Scleral collagen is predominantly type I (7). Collagen types III, V, and VI, VIII, and XII are also found in human sclera (8-12), while the lamina cribrosa... 

Shuttleworth CA. Type VIII collagen. Int J Biochem Cell Biol 1997 29 1145-1148. 

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