GENOMIC ORGANIZATION AND PROMOTER CHARACTERIZATION OF HUMAN CXCR4 GENE

CXCR4 is the receptor for the CMC chemokine SDF1 that has essential fu nctions on embryo organogenesis, immunological functions and T lymphoc yte trafficking. Recently, CXCR4 has drawn unexpected attention as it was recently identified as a co-factor required for entry of lymphotro pic HIV isolates in CD4+ T lymphocytes, CXCR4 is the only SDF1 recepto r identified so far. This suggests that CXCR4 expression is critical f or the biological effects of SDF1, To investigate the mechanisms contr olling both the constitutive and induced expression of CXCR4 receptors we have isolated and characterized the promoter region and determined the genomic structure of the human gene. The CXCR4 gene contains two exons separated by an intronic sequence. A 2.6 kb 5'-flanking region l ocated upstream the CXCR4 open reading frame contains a TATA hox and t he transcription start site characteristic of a functional promoter. T his region also contains putative consensus binding sequences for diff erent transcription factors, some of them associated with the hemopoie sis and lymphocyte development. (C) 1998 Federation of European Bioche mical Societies.