The C5 domain of the collagen VI α3(VI) chain is critical for extracellular microfibril formation and is present in the extracellular matrix of cultured cells

Abstract

Collagen VI, amicrofibrillar protein found in virtually all connective tissues, is composed of three distinct subunits, α1(VI), α2(VI), and α3(VI), which associate intracellularly to form triple helical heterotrimeric monomers then dimers and tetramers. The secreted tetramers associate end-to-end to form beaded microfibrils. Although the basic steps in assembly and the structure of the tetramers and microfibrils are well defined, details of the interacting protein domains involved in assembly are still poorly understood. To explore the role of the C-terminal globular regions in assembly, α3(VI) cDNA expression constructs with C-terminal truncations were stably transfected into SaOS-2 cells. ..