Jensen, Sacha A., Aspinall, Georgia, Handford, Penny A., and UNSPECIFIED (2014) C-terminal propeptide is required for fibrillin-1 secretion and blocks premature assembly through linkage to domains cbEGF41-43. Proceedings of the National Academy of Sciences of the United States of America, 111 (28). pp. 10155-10160.

PDF (Published Version) - Published Version Restricted to Repository staff only

Abstract

Fibrillin microfibrils are 10–12 nm diameter, extracellular matrix assemblies that provide dynamic tissues of metazoan species with many of their biomechanical properties as well as sequestering growth factors and cytokines. Assembly of fibrillin monomers into microfibrils is thought to occur at the cell surface, with initial steps including proprotein processing, multimerization driven by the C terminus, and the head-to-tail alignment of adjacent molecules. At present the mechanisms that regulate microfibril assembly are still to be elucidated. We have used structure-informed protein engineering to create a recombinant, GFP-tagged version of fibrillin-1 (GFP-Fbn) to study this process. Using HEK293T cells transiently transfected with GFP-Fbn constructs, we show that (i) the C-terminal propeptide is an essential requirement for the secretion of full-length fibrillin-1 from cells; (ii) failure to cleave off the C-terminal propeptide blocks the assembly of fibrillin-1 into microfibrils produced by dermal fibroblasts; and (iii) the requirement of the propeptide for secretion is linked to the presence of domains cbEGF41-43, because either deletion or exchange of domains in this region leads to cellular retention. Collectively, these data suggest a mechanism in which the propeptide blocks a key site at the C terminus to prevent premature microfibril assembly.

Item ID:	60803
Item Type:	Article (Research - C1)
ISSN:	1091-6490
Additional Information:	This article is available Open Access via the publisher's website.
Funders:	Arthritis Research UK
Projects and Grants:	Grant 19810
Date Deposited:	04 Mar 2020 22:05
FoR Codes:	06 BIOLOGICAL SCIENCES > 0601 Biochemistry and Cell Biology > 060108 Protein Trafficking @ 50% 06 BIOLOGICAL SCIENCES > 0601 Biochemistry and Cell Biology > 060199 Biochemistry and Cell Biology not elsewhere classified @ 50%
SEO Codes:	97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 100%
	More Statistics