Collagen Type XXV (COL25)

Collagen alpha-1(XXV) chain is is a brain-specific membrane-bound collagen. Proteolytic processing releases CLAC, a soluble form of COL25A1 containing the extracellular collagen domains that associates with senile plaques in Alzheimer disease brains .Northern blot analysis of mouse tissues detected a 4.4-kb Col25a1 transcript in brain only, but RT-PCR showed weak expression in heart, testis, and eye as well. In situ hybridization of mouse brain revealed Col25a1 in neurons of cerebral neocortices, hippocampus, and other subcortical nuclei. SDS-PAGE of transfected human embryonic kidney cells detected COL25A1 monomers of 80 kD under reducing conditions and multimers of 160 and 240 kD under nonreducing conditions, suggesting that COL25A1 assumes a triple-helix configuration.