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Journal of Biomedicine and Biotechnology
Volume 2010 (2010), Article ID 376927, 13 pages
http://dx.doi.org/10.1155/2010/376927
Research Article

The Collagen V Homotrimer Production Is Unexpectedly Favored over the Heterotrimer in Recombinant Expression Systems

1Institut de Biologie et Chimie des Protéines, UMR CNRS 5086, Université Lyon 1, IFR128 Biosciences Gerland, 7 passage du Vercors, 69367 Lyon, France
2Collagen Research Unit, Department of Medical Biochemistry and Molecular Biology, Biocenter Oulu, University of Oulu, 90014 Oulu, Finland
3Centre de Biologie du Développement, CNRS UMR 5547, Université Paul Sabatier, 31062 Toulouse, France
4Bioprocess Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu, 90014 Oulu, Finland
5Sheba Medical Center, Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel-Aviv University, 52621 Tel-Hashomer, Israel

Received 23 October 2009; Revised 19 March 2010; Accepted 20 March 2010

Academic Editor: Chun Tang

Copyright © 2010 Muriel Roulet et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Collagen V, a fibrillar collagen with important functions in tissues, assembles into distinct chain associations. The most abundant and ubiquitous molecular form is the heterotrimer . In the attempt to produce high levels of recombinant collagen V heterotrimer for biomedical device uses, and to identify key factors that drive heterotrimeric chain association, several cell expression systems (yeast, insect, and mammalian cells) have been assayed by cotransfecting the human pro 1(V) and pro 2(V) chain cDNAs. Suprisingly, in all recombinant expression systems, the formation of homotrimers was considerably favored over the heterotrimer. In addition, pepsin-sensitive pro 2(V) chains were found in HEK-293 cell media indicating that these cells lack quality control proteins preventing collagen monomer secretion. Additional transfection with Hsp47 cDNA, encoding the collagen-specific chaperone Hsp47, did not increase heterotrimer production. Double immunofluorescence with antibodies against collagen V -chains showed that, contrary to fibroblasts, collagen V -chains did not colocalized intracellularly in transfected cells. Monensin treatment had no effect on the heterotrimer production. The heterotrimer production seems to require specific machinery proteins, which are not endogenously expressed in the expression systems. The different constructs and transfected cells we have generated represent useful tools to further investigate the mechanisms of collagen trimer assembly.