Folding of the conserved domain but not of flanking regions in the integrin β 2 subunit requires association with the α subunit
Year: 1997
Type: article
Abstract: We have used immunoprecipitation with mAbs to probe folding during biosynthesis of the beta2 integrin subunit of lymphocyte function-associated antigen 1 (LFA-1; CD11a/CD18) before and after association with the alphaL subunit. An evolutionarily conserved region is present in the beta2 subunit between amino acid residues 102 and 344. mAbs to one subregion before the conserved region, and two subregions after the conserved domain, immunoprecipitated both the unassociated beta'2 precursor and mature alphaL/beta2 complex, suggesting portions of these subregions are folded before association with alphaL. An activating mAb to the C-terminal cysteine-rich region, KIM127, preferentially bound to the unassociated beta subunit, suggesting that it may bind to an epitope that is in an alphabeta interface in unactivated LFA-1. By contrast, mAbs to five different epitopes in the conserved region did not react with unassociated beta'2 precursor, suggesting that this region folds after alphaL association and is intimately associated with the alphaL subunit in the alphaL/beta2 complex. mAbs to two different epitopes that involve the border between the conserved region and the C-terminal segment, were fully or partially reactive with the beta'2 precursor, suggesting that this region is partially folded before association with alphaL. The findings suggest that the conserved region is a distinct folding and hence structural unit, and is intimately associated with the alpha subunit.
Authors: Chichi Huang, Chafen Lu, Timothy A. Springer
Institution: Harvard University
Language: English
Subfield: Immunology and Allergy
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funder: National Cancer Institute
OpenAlex ID: W2057979638