Proteasomal degradation of unassembled mutant type I collagen pro-α1(I) chains

Abstract

We have previously shown that type I procollagen pro-α1(I) chains from an osteogenesis imperfecta patient (OI26) with a frameshift mutation resulting in a truncated C-propeptide, have impaired assembly, and are degraded by an endoplasmic reticulum-associated pathway (Lamande, S. R., Chessler, S. D., Golub, S. B., Byers, P. H., Chan, D., Cole, W. G., Sillence, D. O. and Bateman, J. F. (1995) J. Biol. Chem. 270, 8642-8649). To further explore the degradation of procollagen chains with mutant C-propeptides, mouse Mov13 cells, which produce no endogenous pro-α1(I), were stably transfected with a pro-α1(I) expression construct containing a frameshift mutation that predicts the synthesis of a prot..