Sequence-specific binding of human Ets-1 to the T cell receptor alpha gene enhancer.
Expression of the human T cell receptor (TCR) alpha gene is regulated by a T cell-specific transcriptional enhancer that is located 4.5 kilobases (kb) 3' to the C alpha gene segment. The core enhancer contains two nuclear protein binding sites, T alpha 1 and T alpha 2, which are essential for full enhancer activity. T alpha 1 contains a consensus cyclic adenosine monophosphate (cAMP) response element (CRE) and binds a set of ubiquitously expressed CRE binding proteins. In contrast, the transcription factors that interact with the T alpha 2 site have not been defined. In this report, a lambda gt11 expression protocol was used to isolate a complementary DNA (cDNA) that programs the expression of a T alpha 2 binding protein. DNA sequence analysis demonstrated that this clone encodes the human ets-1 proto-oncogene. Lysogen extracts produced with this cDNA clone contained a beta-galactosidase-Ets-1 fusion protein that bound specifically to a synthetic T alpha 2 oligonucleotide. The Ets-1 binding site was localized to a 17-base pair (bp) region from the 3' end of T alpha 2. Mutation of five nucleotides within this sequence abolished both Ets-1 binding and the activity of the TCR alpha enhancer in T cells. These results demonstrate that Ets-1 binds in a sequence-specific fashion to the human TCR alpha enhancer and suggest that this developmentally regulated proto-oncogene functions in regulating TCR alpha gene expression.
Ho
I C
IC
Howard Hughes Medical Institute, Ann Arbor, MI.
Bhat
N K
NK
Gottschalk
L R
LR
Lindsten
T
T
Thompson
C B
CB
Papas
T S
TS
Leiden
J M
JM
D001483:Base Sequence; D001667:Binding, Competitive; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004252:DNA Mutational Analysis; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D015329:Gene Rearrangement, T-Lymphocyte; D006801:Humans; D015151:Immunoblotting; D008969:Molecular Sequence Data; D000090063:Proto-Oncogene Mas; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D050783:Proto-Oncogene Proteins c-ets; D011519:Proto-Oncogenes; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors; D014158:Transcription, Genetic
C494041:ETS1 protein, human; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D011948:Receptors, Antigen, T-Cell; D014157:Transcription Factors; D004247:DNA