title: Transcriptional regulation of Src homology 2 domain-containing leukocyte phosphoprotein of 76 kDa: dissection of key promoter elements.
abstract: SLP-76 (Src homology 2 domain-containing leukocyte phosphoprotein of 76 kDa) is an adaptor molecule expressed in all hemopoietic cell lineages except mature B cells and is known to play critical roles in the function of T cells, mast cells, and platelets and in vascular differentiation. Although great progress has been achieved in our understanding of SLP-76 function, little is known about the mechanisms regulating its expression. In this study we report the initial characterization of essential elements that control SLP-76 transcription. We identify several DNase I-hypersensitive sites in the SLP-76 locus, with a prominent site located in its promoter region. This site exists in T cells and monocytic cells, but not in B cells or fibroblasts. Using transient transfection assays, we identify a 507-bp fragment containing the 5'-untranslated region of the first exon and the immediate upstream sequence that confers transcriptional activation in T cells and monocytic cells, but not in B cells. Analysis of the 5' ends of SLP-76 transcripts reveals differential regulation of SLP-76 transcription initiation between T cells and monocytic cells. Mutational and gel-shift analyses further indicate a critical role within this region for a binding site for Ets family transcription factors. The present study provides the first data to address the mechanisms controlling SLP-76 transcription by providing evidence for several key cis-regulatory elements in the promoter region.
authors.affiliation: Signal Transduction Program, The Abramson Family Cancer Research Institute, and Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Zhong
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Maltzman
authors.forename: Ehmonie A
authors.initials: EA
authors.lastname: Hainey
authors.forename: Gary A
authors.initials: GA
authors.lastname: Koretzky
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D020029:Base Pairing; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D019070:Cell Lineage / Q000235:genetics; D003850:Deoxyribonuclease I / Q000378:metabolism; D017930:Genes, Reporter; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D006825:Hybridomas; D019169:Jurkat Cells; D051379:Mice; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000276:immunology; D011518:Proto-Oncogene Proteins / Q000502:physiology; D050783:Proto-Oncogene Proteins c-ets; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000502:physiology; D024363:Transcription Initiation Site; D014158:Transcription, Genetic; D015854:Up-Regulation / Q000276:immunology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D005819:Genetic Markers; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D011948:Receptors, Antigen, T-Cell; C092947:SLP-76 signal Transducing adaptor proteins; D014157:Transcription Factors; D003850:Deoxyribonuclease I