A novel fibronectin binding site required for fibronectin fibril growth during matrix assembly

Citation
Jl. Sechler et al., A novel fibronectin binding site required for fibronectin fibril growth during matrix assembly, J CELL BIOL, 154(5), 2001, pp. 1081-1088
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
JOURNAL OF CELL BIOLOGY
ISSN journal
0021-9525 → ACNP
Volume
154
Issue
5
Year of publication
2001
Pages
1081 - 1088
Database
ISI
SICI code
0021-9525(20010903)154:5<1081:ANFBSR>2.0.ZU;2-6
Abstract
Fibronectin (FN) assembly into a fibrillar extracellular matrix is a stepwi se process requiring participation from multiple FN domains. Fibril formati on is regulated in part by segments within the first seven type III repeats (III1-7). To define the specific function(s) of this region, recombinant F Ns (recFNs) containing an overlapping set of deletions were tested for the ability to assemble into fibrils. Surprisingly, recFN lacking type III repe at III1 (FN Delta III1), which contains a cryptic FN binding site and has b een suggested to be essential for fibril assembly, formed a matrix identica l in all respects to a native FN matrix. Similarly, displacement of the cel l binding domain in repeats III9-10 to a position close to the NH2-terminal assembly domain, as well as a large deletion spanning repeats III4-7, had no effect on assembly. in contrast, two deletions that included repeat III2 , Delta III1-2 and Delta III2-5, caused significant reductions in fibril el ongation, although binding of FN to the cell surface and initiation of asse mbly still proceeded. Using individual repeats in binding assays, we show t hat III2 but not III1 contains an FN binding site. Thus, these results pinp oint repeat III2 as an important module for FN-FN interactions during fibri l growth.