Characterization of promoter region and genomic structure of the murine and human genes encoding Src like adapter protein

Abstract

Src-like adapter protein (SLAP) was identified as a signaling molecule in a yeast two-hybrid system using the cytoplasmic domain of EphA2, a receptor protein tyrosine kinase (Pandey et al., 1995. Characterization of a novel Src-like adapter protein that associates with the Eck receptor tyrosine kinase. J. Biol. Chem. 270, 19201–19204). It is very similar to members of the Src family of cytoplasmic tyrosine kinases in that it contains very homologous SH3 and SH2 domains (Abram and Courtneidge, 2000. Src family tyrosine kinases and growth factor signaling. Exp. Cell. Res. 254, 1–13.). However, instead of a kinase domain at the C-terminus, it contains a unique C-terminal region. In order to exclude the possibility that an alternative form exists, we have isolated genomic clones containing the murine Slap gene as well as the human SLA gene. The coding regions of murine Slap and human SLA genes contain seven exons and six introns. Absence of any kinase domain in the genomic region confirm its designation as an adapter protein. Additionally, we have cloned and sequenced approximately 2.6 kb of the region 5′ to the initiator methionine of the murine Slap gene. When subcloned upstream of a luciferase gene, this fragment increased the transcriptional activity about 6-fold in a human Jurkat T cell line and approximately 52-fold in a murine T cell line indicating that this region contains promoter elements that dictate SLAP expression. We have also cloned the promoter region of the human SLA gene. Since SLAP is transcriptionally regulated by retinoic acid and by activation of B cells, the cloning of its promoter region will permit a detailed analysis of the elements required for its transcriptional regulation.