The transforming growth factor-beta-inducible matrix protein (beta)ig-h3 interacts with fibronectin.
Proper growth and development require the orderly synthesis and deposition of individual components of the extracellular matrix (ECM) into well ordered networks. Once formed, the ECM maintains tissue structure and houses resident cells. One ECM component, (beta)ig-h3, is a highly conserved transforming growth factor-beta-inducible protein that has been hypothesized to function as a bifunctional linker between individual matrix components and resident cells. To gain insights into its physiological function, full-length (beta)ig-h3 protein was produced using a baculovirus expression system and purified under native conditions. Human fibroblasts attached and spread on (beta)ig-h3-coated plates and developed actin stress fibers. Purified (beta)ig-h3 binds fibronectin (FN) and type I collagen (Col I) but does not bind gelatin. Using defined fragments of FN, we localized the (beta)ig-h3 recognition region to the gelatin/collagen binding domain present in the N-terminal region of the FN molecule. Our results identify FN and Col I as two ligands of (beta)ig-h3 in the ECM.
Billings
Paul C
PC
Department of Orthopedic Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA. pbilling@mail.med.upenn.edu
Whitbeck
J Charles
JC
Adams
Christopher S
CS
Abrams
William R
WR
Cohen
Arthur J
AJ
Engelsberg
Beatrice N
BN
Howard
Pamela S
PS
Rosenbloom
Joel
J
D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D002448:Cell Adhesion / Q000502:physiology*; D002460:Cell Line; D002478:Cells, Cultured; D017931:DNA Primers; D005109:Extracellular Matrix / Q000502:physiology*; D016326:Extracellular Matrix Proteins; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D016366:Open Reading Frames; D011994:Recombinant Proteins / Q000378:metabolism; D018411:Spodoptera; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D001743:Urinary Bladder / Q000502:physiology; D000099222:betaIG-H3 Protein
D017931:DNA Primers; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D009363:Neoplasm Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein