Specific expression of a tyrosine kinase gene, blk, in B lymphoid cells.
Several pathways of transmembrane signaling in lymphocytes involve protein-tyrosine phosphorylation. With the exception of p56lck, a tyrosine kinase specific to T lymphoid cells that associates with the T cell transmembrane proteins CD4 and CD8, the kinases that function in these pathways are unknown. A murine lymphocyte complementary DNA that represents a new member of the src family has now been isolated and characterized. This complementary DNA, termed blk (for B lymphoid kinase), specifies a polypeptide of 55 kilodaltons that is related to, but distinct from, previously identified retroviral or cellular tyrosine kinases. The protein encoded by blk exhibits tyrosine kinase activity when expressed in bacterial cells. In the mouse and among cell lines, blk is specifically expressed in the B cell lineage. The tyrosine kinase encoded by blk may function in a signal transduction pathway that is restricted to B lymphoid cells.
Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
S M
SM
Dymecki
J E
JE
Niederhuber
S V
SV
Desiderio
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000201:enzymology*; D001483:Base Sequence; D003062:Codon; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D015870:Gene Expression; D051379:Mice; D008969:Molecular Sequence Data; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D015398:Signal Transduction; D019061:src-Family Kinases / Q000235:genetics*
D003062:Codon; D004247:DNA; D011505:Protein-Tyrosine Kinases; C000592904:B lymphoid kinase, mouse; D019061:src-Family Kinases