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Effect of integrin beta 2 subunit truncations on LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18) assembly, surface expression, and function.
- Source :
-
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2000 Sep 01; Vol. 165 (5), pp. 2574-81. - Publication Year :
- 2000
-
Abstract
- LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18) are members of the beta2 integrins involved in leukocyte function during immune and inflammatory responses. We aimed to determine a minimized beta2 subunit that forms functional LFA-1 and Mac-1. Using a series of truncated beta2 variants, we showed that the subregion Q23-D300 of the beta2 subunit is sufficient to combine with the alphaL and alphaM subunits intracellularly. However, only the beta2 variants terminating after Q444 promote cell surface expression of LFA-1 and Mac-1. Thus, the major cysteine-rich region and the three highly conserved cysteine residues at positions 445, 447, and 449 of the beta2 subunit are not required for LFA-1 and Mac-1 surface expression. The surface-expressed LFA-1 variants are constitutively active with respect to ICAM-1 adhesion and these variants express the activation reporter epitope of the mAb 24. In contrast, surface-expressed Mac-1, both the wild type and variants, require 0. 5 mM MnCl2 for adhesion to denatured BSA. These results suggest that the role of the beta2 subunit in LFA-1- and Mac-1-mediated adhesion may be different.
- Subjects :
- Animals
CD18 Antigens physiology
COS Cells
Cysteine genetics
Cysteine physiology
Cytoplasm genetics
Cytoplasm metabolism
Cytoplasm physiology
Dimerization
Genetic Variation
Genetic Vectors chemical synthesis
Humans
Ligands
Lymphocyte Function-Associated Antigen-1 biosynthesis
Lymphocyte Function-Associated Antigen-1 genetics
Lymphocyte Function-Associated Antigen-1 physiology
Macrophage-1 Antigen biosynthesis
Macrophage-1 Antigen genetics
Macrophage-1 Antigen physiology
Membrane Proteins genetics
Membrane Proteins metabolism
Membrane Proteins physiology
Peptide Fragments genetics
Peptide Fragments physiology
Protein Processing, Post-Translational immunology
Solubility
Transfection
CD18 Antigens genetics
Lymphocyte Function-Associated Antigen-1 metabolism
Macrophage-1 Antigen metabolism
Membrane Proteins biosynthesis
Sequence Deletion
Subjects
Details
- Language :
- English
- ISSN :
- 0022-1767
- Volume :
- 165
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Publication Type :
- Academic Journal
- Accession number :
- 10946284
- Full Text :
- https://doi.org/10.4049/jimmunol.165.5.2574