title: A prominent role for activator protein-1 in the transcription of the human 2B4 (CD244) gene in NK cells.
abstract: The cell surface glycoprotein 2B4 (CD244) of the Ig superfamily is involved in the regulation of NK and T lymphocyte functions. We have recently identified CD48 as the high affinity counterreceptor for 2B4 in both mice and humans. The cytoplasmic domain of 2B4 associates with src homology 2 domain-containing protein or signaling lymphocyte activation molecule-associated protein, whose mutation is the underlying genetic defect in the X-linked lymphoproliferative syndrome. In this study, we report the molecular cloning and characterization of the human 2B4 (h2B4) promoter. Through primer extension analysis, we found that the transcription of the h2B4 gene initiates at multiple start sites. We isolated h2B4 genomic clones and PCR amplified the 5' untranslated region containing the promoter elements. We have identified a functional AP-1 site that lies between (-106 to -100) through transient transfection analysis in YT cells, a human NK cell line. EMSAs with Abs specific for various protein factors of the AP-1 family revealed that multiple members of the Jun family are involved in the regulation of the h2B4 gene. Mutation of the AP-1 site not only abolishes protein/DNA interactions but also promoter activity. These results demonstrate a significant role for AP-1 in the transcriptional regulation of the h2B4 gene.
authors.affiliation: Department of Molecular Biology and Immunology and Institute for Cancer Research, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX 76107, USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Chuang
authors.forename: H T
authors.initials: HT
authors.lastname: Pham
authors.forename: P R
authors.initials: PR
authors.lastname: Kumaresan
authors.forename: P A
authors.initials: PA
authors.lastname: Mathew
mesh_terms: D020121:5' Untranslated Regions / Q000302:isolation & purification; D015703:Antigens, CD; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics / Q000276:immunology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis; D011971:Receptors, Immunologic; D000071176:Signaling Lymphocytic Activation Molecule Family; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014158:Transcription, Genetic / Q000276:immunology*; D014407:Tumor Cells, Cultured
chemical_list: D020121:5' Untranslated Regions; D015703:Antigens, CD; C084093:CD244 protein, human; D004268:DNA-Binding Proteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D000071176:Signaling Lymphocytic Activation Molecule Family; D018808:Transcription Factor AP-1