Small Collagenous Proteins Present during the Molt in Caenorhabditis elegans

Immunoblotting experiments using antibodies directed against the large collagenous cuticle proteins of Caenorhabditis elegans revealed a class of small collagenous proteins (CP) of apparent molecular weight 38,000-52,000 present during the L4 to adult molt. These CP are smaller than most vertebrate collagens characterized to date and share many characteristics with the small collagenous products translated in vitro from RNA isolated at this molt. C. elegans collagen genes, collagen-coding mRNA, and collagenous in vitro products that have been characterized are also small. Detection of small CP in vivo in C. elegans thus lends further support to the hypothesis that such small collagenous proteins are the primary gene product precursors to the larger collagenous proteins isolated from the C. elegans cuticle.