Cloning of human lymphocyte-specific interferon regulatory factor (hLSIRF/hIRF4) and mapping of the gene to 6p23-p25

The interferon regulatory factor (IRF) genes encode a family of transcription factors involved in the transcriptional regulation of interferon and the interferon stimulated genes through recognition of the interferon stimulated response element. We previously reported the cloning of a murine lymphocyte-specific IRF (mLSIRF), which was rapidly induced following B- or T-cell receptor crosslinking, To study the role of LSIRF in human lymphocyte development, we have cloned the complete 5.3-kb cDNA for the human homolog (hLSIRF). hLSIRF is a protein of 450 amino acids with a predicted molecular weight of 51.6 kDa and possesses 92% identity at the amino acid level to mLSIRF, including near identity in the DNA-binding domain. In Northern blot analysis, a single transcript of similar to 5 kb was highly expressed in spleen and peripheral blood lymphocyte, hLSIRF mRNA was rapidly induced in peripheral T cells after crosslinking the T-cell receptor, Analysis of tumor cell lines showed that hLSIRF mRNA was basally expressed in most B- but not T-cell lines, Surprisingly hLSIRF mRNA was also found in the melanoma line G361 and is expressed in normal melanocytes as well, Sequence hom a genomic clone for hLSIRF was compared to that from mouse and revealed an identical exon-intron structure and a conserved PU.1-binding motif in the promoter, By FISH analysis, hLSIRF was mapped to 6p23-p25. (C) 1996 Academic Press, Inc.