Isolation and characterization of nuclear proteins that bind to T cell receptor V beta decamer motif.
TCR V beta promoter contains a highly conserved decamer homologous to cAMP response element (CRE). Recent studies have identified this CRE decamer as the dominant transcription-activating element within the TCR V beta promoter. We have isolated cDNA clones, TCR-ATF1 and TCR-ATF2, encoding DNA-binding proteins that recognize this CRE motif. The nucleotide sequence of TCR-ATF1 has not previously been reported, whereas that of TCR-ATF2 was homologous to CRE-BP1, ATF-2, and mXBP. Both TCR-ATF1 and TCR-ATF2 shared a conserved leucine zipper and DNA binding motif with other CRE-binding proteins. TCR-ATF1 and TCR-ATF2 were expressed in all cell lines examined and in mouse embryos as early as 12.5 days. Despite binding to the same CRE motif, TCR-ATF1 and TCR-ATF2 were different from CREB in the fine nucleotide specificity. TCR-ATF bound methylated CRE and CRE mutant M4 (4C----G) that were not recognized by CREB. Additionally, TCR-ATF1 weakly recognized two other single nucleotide mutants of V beta-CRE that were not bound by TCR-ATF2 and CREB. We have further demonstrated that TCR beta-chain expression was immediately activated by cAMP. Such induction is likely mediated through V beta-CRE sequence, because the inclusion of V beta-CRE in a vector with minimum promoter (pBLCAT2) conferred the cAMP inducibility of CAT activity.
Lee
M R
MR
Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, R.O.C.
Chung
C S
CS
Liou
M L
ML
Wu
M
M
Li
W F
WF
Hsueh
Y P
YP
Lai
M Z
MZ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D015870:Gene Expression; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D016693:Receptors, Antigen, T-Cell, alpha-beta; D014157:Transcription Factors