β2 (CD18) Mutations Abolish Ligand Recognition by I Domain Integrins LFA-1 ( αLβ2, CD11a/CD18) and MAC-1 ( αMβ2, CD11b/CD18)
Year: 1995
Type: article
Abstract: The "I" domains of the beta 2 (CD18) leukocyte integrins are implicated in ligand binding function. Moreover, rather than recognizing linear peptide sequences, this class of integrins generally recognizes multiple discontinuous sites on immunoglobulin superfamily adhesion receptors. A conserved cluster of oxygenated residues is involved in ligand recognition by beta 1 and beta 3 integrins. In the present study, we evaluated the role of this region in the I domain-containing beta 2 integrins. Recombinant alpha L beta 2 (LFA-1, CD11a/CD18) and alpha M beta 2 (MAC-1, CD11b/CD18) were expressed on COS cells, and function was assessed by adhesion to ICAM-1 or iC3b, respectively. Alanine substitution at position Asp134 or Ser136 in beta 2 produced a complete loss in the capacity of both alpha L beta 2 and alpha M beta 2 to support cell adhesion. In contrast, substitution at Asp128 or Ser138 resulted in loss of beta 2 surface expression when co-transfected with alpha L (CD11a) or alpha M (CD11b). These data provide the first evidence for involvement of the beta 2 subunit in ligand binding to I domain integrins.
Source: Journal of Biological Chemistry
DOI: 10.1074/jbc.270.1.94
Authors: Mary Lynn Bajt, Tom Goodman, Sarah Lea McGuire
Language: English
Subfield: Immunology and Allergy
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W2034234555