title: GATA-3 dominant negative mutant. Functional redundancy of the T cell receptor alpha and beta enhancers.
abstract: The GATA family of transcription factors regulates a wide variety of genes, including those involved in differentiation of erythrocytes and T lymphocytes. We report here the creation of a dominant negative mutant of GATA-3, KRR, which effectively blocks wild-type GATA-1, GATA-2, and GATA-3 transactivation when co-expressed in transient assays. KRR was generated by site-directed mutagenesis while investigating a putative activation domain of GATA-3, located between its two zinc fingers. The GATA-3 KRR mutation does not affect expression, nuclear translocation, or the ability to bind to a consensus GATA sequence. KRR can suppress the activity of the minimal T cell receptor (TCR) alpha and beta enhancers by 12- and 3.4-fold, respectively. However, KRR did not have a significant effect on the activity of larger TCR-alpha and -beta enhancer fragments. Thus, functional redundancy in the TCR-alpha and -beta enhancers can compensate for the loss of GATA-3 activity.
authors: Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200.
authors: V M
authors: VM
authors: Smith
authors: P P
authors: PP
authors: Lee
authors: S
authors: S
authors: Szychowski
authors: A
authors: A
authors: Winoto
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D050990:GATA3 Transcription Factor; D017353:Gene Deletion; D005799:Genes, Dominant; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D017354:Point Mutation; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D015183:Restriction Mapping; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D016335:Zinc Fingers
chemical_list: D004268:DNA-Binding Proteins; D050990:GATA3 Transcription Factor; C494749:GATA3 protein, human; D009838:Oligodeoxyribonucleotides; D016693:Receptors, Antigen, T-Cell, alpha-beta; D015534:Trans-Activators; D014157:Transcription Factors