Structure and regulation of the gene encoding avian inhibitor of nuclear factor kappa B-alpha.
The Rel/NF-kappa B family of transcription factors exist in the cytoplasm as inactive complexes in association with an inhibitory protein called I kappa B-alpha. We have isolated a clone containing the avian I kappa B-alpha gene from a chicken genomic library. Avian I kappa B-alpha is devoid of any recognizable promoter elements, i.e., TATA and CAAT boxes; however, the 5'-UTR of the gene contains the initiator elements frequently found in TATA-less genes. Avian I kappa B-alpha contains seven putative Rel/NF-kappa B binding sites. A CAT reporter construct containing the 5' upstream region of I kappa B-alpha was expressed when transfected into cells which produce I kappa B-alpha. This construct, however, was not expressed in cells in which I kappa B-alpha activity was not induced, indicating that the regulatory elements which promote I kappa B-alpha expression are contained within 1000 nt of the transcription start site. Southern analysis suggests that I kappa B-alpha is present as a single-copy gene per haploid genome and is expressed in avian hematopoietic tissues, as well as lymphoid cells transformed by avian reticuloendotheliosis virus (REV-T).
Department of Microbiology, University of Texas at Austin 78712-1095, USA.
V A
VA
Krishnan
J D
JD
Schatzle
C M
CM
Hinojos
H R
HR
Bose
D000818:Animals; D001483:Base Sequence; D002645:Chickens / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D005786:Gene Expression Regulation; D005796:Genes; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D020672:I-kappa B Proteins; D008221:Lymphoid Tissue / Q000378:metabolism; D008969:Molecular Sequence Data; D000072000:NF-KappaB Inhibitor alpha; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D012333:RNA, Messenger; D000072000:NF-KappaB Inhibitor alpha