Three novel collagen VI chains, α4(VI), α5(VI), and α6(VI)
Date
2008
Authors
Fitzgerald, J.
Rich, C.
Zhou, F.H.
Hansen, U.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Journal of Biological Chemistry, 2008; 283(29):20170-20180
Statement of Responsibility
Jamie Fitzgerald, Cathleen Rich, Fiona H. Zhou, and Uwe Hansen
Conference Name
Abstract
Wereport the identification of three new collagen VI genes at a single locus on human chromosome 3q22.1. The three new genes are COL6A4, COL6A5, and COL6A6 that encode the α4(VI), α5(VI), and α6(VI) chains. In humans, the COL6A4 gene has been disrupted by a chromosome break. Each of the three new collagen chains contains a 336-amino acid triple helix flanked by seven N-terminal von Willebrand factor A-like domains and two (α4 and α6 chains) or three (α5 chain) C-terminal von Willebrand factor A-like domains. In humans,mRNA expression of COL6A5 is restricted to a few tissues, including lung, testis, and colon. In contrast, the COL6A6 gene is expressed in a wide range of fetal and adult tissues, including lung, kidney, liver, spleen, thymus, heart, and skeletal muscle. Antibodies to the α6(VI) chain stained the extracellular matrix of human skeletal and cardiac muscle, lung, and the territorial matrix of articular cartilage. In cell transfection and immunoprecipitation experiments, mouse α4(VI)N6-C2 chain co-assembled with endogenous α1(VI) and α2(VI) chains to form trimeric collagen VI molecules that were secreted from the cell. In contrast, σ5(VI)N5-C1 and σ6(VI)N6-C2 chains did not assemble with σ1(VI) and σ2(VI) chains and accumulated intracellularly. We conclude that the σ4(VI)N6-C2 chain contains all the elements necessary for trimerization with σ1(VI) and σ2(VI). In summary, the discovery of three additional collagen VI chains doubles the collagen VI family and adds a layer of complexity to collagen VI assembly and function in the extracellular matrix.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
© 2008 by The American Society for Biochemistry and Molecular Biology, Inc. This is an Open Access article under the CC BY license.