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.
Pubmed ID: 7682714 RIS Download
Amino Acid Sequence | Antibodies | Antibodies, Monoclonal | Antigens, CD45 | B-Lymphocytes | Blood Proteins | Electrophoresis, Polyacrylamide Gel | Humans | Immunoblotting | Molecular Sequence Data | Molecular Weight | Peptide Fragments | Phosphoproteins | Phosphotyrosine | Protein-Tyrosine Kinases | Receptors, Antigen, T-Cell | Signal Transduction | Tumor Cells, Cultured | Tyrosine