ISSN:
0730-2312
Keywords:
assembly of type I collagen
;
COOH-terminal propeptide
;
pesin-resistant heterotrimers
;
disulfide bonds
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Collagen biosynthesis is a complex process that begins with the association of three procollagen chains. A series of conserved intra- and interchain disulfide bonds in the carboxyl-terminal region of the procollagen chains, or C-propeptide, has been hypothesized to play an important role in the nucleation and alignment of the chains. We tested this hypothesis by analyzing the ability of normal and cysteine-mutated pro-α2(I) chains to assemble into type I collagen heterotrimers when expressed in a cell line (D2) that produces only endogenous pro-α1(I). Pro-α2(I) chains containing single or double cysteine mutations that disrupted individual intra- or interchain disulfide bonds were able to form pepsin resistant type I collagen with pro-α1(I), indicating that individual disulfide bonds were not critical for assembly of the pro-α2(I) chain with pro-α1(I). Pro-α2(I) chains containing a triple cysteine mutation that disrupted both intrachain disulfide bonds were not able to form pepsin resistant type I collagen with pro-α1(I). Therefore, disruption of both pro-α2(I) intrachain disulfide bonds prevented the production and secretion of type I collagen heterotrimers. Although none of the individual disulfide bonds is essential for assembly of the procollagen chains, the presence of at least one intrachain disulfide bond may be necessary as a structural requirement for chain association or to stabilize the protein to prevent intracellular degradation. J.Cell. Biochem. 71:233-242, 1998. © 1998 Wiley-Liss, Inc.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
