This gene encodes a brain-specific membrane associated collagen. A product of proteolytic processing of the encoded protein, CLAC (collagenous Alzheimer amyloid plaque component), binds to amyloid beta-peptides found in Alzheimer amyloid plaques but CLAC inhibits rather than facilitates amyloid fibril elongation (PMID: 16300410). A study of over-expression of this collagen in mice, however, found changes in pathology and behavior suggesting that the encoded protein may promote amyloid plaque formation (PMID: 19548013). Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2011],caution:The pyrrolidone carboxylic acid reported in PubMed:11927537 probably formed artifactually from Glu-113 during the extraction procedure in 70% formic acid. In PubMed:15522881, the protein was found to have unblocked Glu at the N-terminus.,function:Inhibits fibrillization of beta amyloid peptide during the elongation phase. Has also been shown to assemble amyloid fibrils into protease-resistant aggregates. Binds heparin.,PTM:Glycosylated.,PTM:Hydroxylated on 11% of proline residues and 49% of lysine residues.,PTM:Undergoes proteolytic cleavage by furin protease to yield the soluble collagen-like Alzheimer amyloid plaque component.,similarity:Contains 7 collagen-like domains.,subcellular location:After proteolytic cleavage, CLAC is secreted.,subunit:Forms homodimers and homotrimers. Binds to the fibrillized forms of beta amyloid peptide 40 (beta-APP40) and beta amyloid peptide 42 (beta-APP42). Found associated with beta-APP42 more frequently than with beta-APP40.,tissue specificity:Expressed predominantly in brain. Deposited preferentially in primitive or neuritic amyloid plaques which are typical of Alzheimers disease.,
