The cytoplasmic domain of the CD8 alpha-chain is required for its interaction with p56lck.
The CD8 glycoprotein expressed on the surface of CTLs is a heterodimer composed of alpha (Lyt-2) and beta (Lyt-3) chains. Recent studies have shown that CD4 and CD8 are physically associated with a T cell-specific protein-tyrosine kinase p56lck. Our previous experiments have suggested strongly that p56lck interacts directly with CD4 and CD8 molecules. The present report using cytoplasmic deletion mutants of the CD8 alpha-chain gene has extended our observations to demonstrate unequivocally that the cytoplasmic domain of the CD8 alpha chain is responsible for interaction with p56lck. The data has also confirmed the importance of the conserved twelve amino acid sequence motif of the CD8 alpha cytoplasmic domain in complex formation with p56lck.
Yao
L
L
Department of medical Chemistry, Kyoto University School of Medicine, Japan.
Nakauchi
H
H
Honjo
T
T
Kawakami
T
T
D000595:Amino Acid Sequence; D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics / Q000378:metabolism*; D000950:Antigens, Ly / Q000235:genetics; D001483:Base Sequence; D016827:CD8 Antigens; D002460:Cell Line; D002872:Chromosome Deletion; D003593:Cytoplasm / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D006801:Humans; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D008969:Molecular Sequence Data; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D014162:Transfection
D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D016827:CD8 Antigens; D011505:Protein-Tyrosine Kinases; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck)