Transcriptional regulation of the human CD3 gamma gene: the TATA-less CD3 gamma promoter functions via an initiator and contiguous Sp-binding elements.
Growing evidence that the CD3gamma gene is specifically targeted in some T cell diseases focused our attention on the need to identify and characterize the elusive elements involved in CD3gamma transcriptional control. In this study, we show that while the human CD3gamma and CD3delta genes are oriented head-to-head and separated by only 1.6 kb, the CD3gamma gene is transcribed from an independent but weak, lymphoid-specific TATA-less proximal promoter. Using RNA ligase-mediated rapid amplification of cDNA ends, we demonstrate that a cluster of transcription initiation sites is present in the vicinity of the primary core promoter, and the major start site is situated in a classical initiator sequence. A GT box immediately upstream of the initiator binds Sp family proteins and the general transcription machinery, with the activity of these adjacent elements enhanced by the presence of a second GC box 10 nt further upstream. The primary core promoter is limited to a sequence that extends upstream to -15 and contains the initiator and GT box. An identical GT box located approximately 50 nt from the initiator functions as a weak secondary core promoter and likely generates transcripts originating upstream from the +1. Finally, we show that two previously identified NFAT motifs in the proximal promoter positively (NFATgamma(1)) or negatively (NFATgamma(1) and NFATgamma(2)) regulate expression of the human CD3gamma gene by their differential binding of NFATc1 plus NF-kappaB p50 or NFATc2 containing complexes, respectively. These data elucidate some of the mechanisms controlling expression of the CD3gamma gene as a step toward furthering our understanding of how its transcription is targeted in human disease.
Badran
Bassam M
BM
Laboratory of Experimental Hematology, Bordet Institute, Faculty of Medicine, University of Brussels, Brussels, Belgium.
Kunstman
Kevin
K
Stanton
Jennifer
J
Moschitta
Maria
M
Zerghe
Anne
A
Akl
Haidar
H
Burny
Arsène
A
Wolinsky
Steven M
SM
Willard-Gallo
Karen E
KE
D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D017252:CD3 Complex / Q000096:biosynthesis* / Q000235:genetics* / Q000502:physiology; D002460:Cell Line; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D018900:Dinucleotide Repeats / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D019169:Jurkat Cells; D008969:Molecular Sequence Data; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins / Q000235:genetics* / Q000502:physiology; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D011401:Promoter Regions, Genetic / Q000502:physiology*; D017384:Sequence Deletion; D016329:Sp1 Transcription Factor / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D016385:TATA Box; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology; D024363:Transcription Initiation Site / Q000502:physiology*
D017252:CD3 Complex; C452842:CD3 antigen, gamma chain; D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; C494003:NFATC1 protein, human; C494006:NFATC2 protein, human; D009687:Nuclear Proteins; D016329:Sp1 Transcription Factor; D014157:Transcription Factors