First Author | Cheng AM | Year | 1995 |
Journal | Nature | Volume | 378 |
Issue | 6554 | Pages | 303-6 |
PubMed ID | 7477353 | Mgi Jnum | J:29797 |
Mgi Id | MGI:77315 | Doi | 10.1038/378303a0 |
Citation | Cheng AM, et al. (1995) Syk tyrosine kinase required for mouse viability and B-cell development. Nature 378(6554):303-6 |
abstractText | The Syk cytoplasmic protein-tyrosine kinase has two amino-terminal SH2 domains and a carboxy-terminal catalytic domain. Syk, and its close relative ZAP-70, are apparently pivotal in coupling antigen- and Fc-receptors to downstream signalling events. Syk associates with activated Fc receptors, the T cell receptor complex and the B-cell antigen-receptor complex (BCR) in immature and mature B lymphocytes. On receptor activation, the tandem SH2 domains of Syk bind dual phosphotyrosine sites in the conserved ITAM motifs of receptor signalling chains, such as the immunoglobulin alpha and beta-chains of the BCR, leading to Syk activation. Here we have investigated Syk function in vivo by generating a mouse strain with a targeted mutation in the syk gene. Homozygous syk mutants suffered severe haemorrhaging as embryos and died perinatally, indicating that Syk has a critical role in maintaining vascular integrity or in wound healing during embryogenesis. Analysis of syk-/- lymphoid cells showed that the syk mutation impaired the differentiation of B-lineage cells, apparently by disrupting signalling from the pre-BCR complex and thereby preventing the clonal expansion, and further maturation, of pre-B cells. |