Identification of HS1 protein as a major substrate of protein-tyrosine kinase(s) upon B-cell antigen receptor-mediated signaling.
Crosslinking of membrane-bound immunoglobulins, which are B-cell antigen receptors, causes proliferation and differentiation of B cells or inhibition of their growth. The receptor-mediated signaling involves tyrosine phosphorylation of cellular proteins and rapid activation of Src-like kinases. The amino acid sequences of five proteolytic peptides of p75, a major substrate of protein-tyrosine(s) in the signaling, showed that p75 is the human HS1 gene product. The HS1 gene is expressed specifically in hematopoietic cells and encodes p75HS1, which carries both helix-turn-helix and Src homology 3 motifs. p75HS1 showed rapid tyrosine phosphorylation and association with a Src-like kinase, Lyn, after crosslinking of membrane-bound IgM. Thus, p75HS1 may be an important substrate of Lyn and possibly other protein-tyrosine kinases upon B-cell antigen receptor-mediated signaling.
Yamanashi
Y
Y
Department of Oncology, University of Tokyo, Japan.
Okada
M
M
Semba
T
T
Yamori
T
T
Umemori
H
H
Tsunasawa
S
S
Toyoshima
K
K
Kitamura
D
D
Watanabe
T
T
Yamamoto
T
T
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000906:Antibodies; D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000276:immunology* / Q000502:physiology; D001798:Blood Proteins / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D015151:Immunoblotting; D017493:Leukocyte Common Antigens / Q000302:isolation & purification; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000302:isolation & purification; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis
D048868:Adaptor Proteins, Signal Transducing; D000906:Antibodies; D000911:Antibodies, Monoclonal; D001798:Blood Proteins; C061909:HCLS1 protein, human; D010446:Peptide Fragments; D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D017493:Leukocyte Common Antigens