The effects of cysteine to alanine mutations of CD18 on the expression and adhesion of the CD11/CD18 integrins.
Of the 56 cysteines in the extracellular domain of the CD18 antigen (beta2 integrin subunit), corresponding ones are not found in 12 positions in the beta4, beta7, or beta8 integrin subunits. These 12 cysteines were mutated to alanines, either singly or in pairs, in CD18. All these mutants can support the expression of all three CD11/CD18 integrins. Transfectants expressing these variant integrins are generally more adhesive than the wild-type, suggesting that the cysteine residues, perhaps by engaging in disulphide bonds, may contribute to the maintenance of the CD11/CD18 integrins in a resting state.
Nolan
S M
SM
The MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU, Oxford, UK.
Mathew
E C
EC
Scarth
S L
SL
Al-Shamkhani
A
A
Law
S K
SK
D000409:Alanine / Q000235:genetics; D000818:Animals; D018821:CD18 Antigens / Q000235:genetics / Q000378:metabolism*; D019556:COS Cells; D002448:Cell Adhesion; D002522:Chlorocebus aethiops; D003545:Cysteine / Q000235:genetics; D015870:Gene Expression; D014644:Genetic Variation; D016167:Integrin alphaXbeta2 / Q000235:genetics / Q000378:metabolism*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000235:genetics / Q000378:metabolism*; D016177:Macrophage-1 Antigen / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D014162:Transfection
D018821:CD18 Antigens; D016167:Integrin alphaXbeta2; D016169:Lymphocyte Function-Associated Antigen-1; D016177:Macrophage-1 Antigen; D003545:Cysteine; D000409:Alanine