Ko L J, Engel J D
Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208-3500.
Mol Cell Biol. 1993 Jul;13(7):4011-22. doi: 10.1128/mcb.13.7.4011-4022.1993.
Members of the GATA family of transcription factors, which are related by a high degree of amino acid sequence identity within their zinc finger DNA-binding domains, each show distinct but overlapping patterns of tissue-restricted expression. Although GATA-1, -2, and -3 have been shown to recognize a consensus sequence derived from regulatory elements in erythroid cell-specific genes, WGATAR (in which W indicates A/T and R indicates A/G), the potential for more subtle differences in the binding preferences of each factor has not been previously addressed. By employing a binding selection and polymerase chain reaction amplification scheme with randomized oligonucleotides, we have determined the binding-site specificities of bacterially expressed chicken GATA-1, -2, and -3 transcription factors. Whereas all three GATA factors bind an AGATAA erythroid consensus motif with high affinity, a second, alternative consensus DNA sequence, AGATCTTA, is also recognized well by GATA-2 and GATA-3 but only poorly by GATA-1. These studies suggest that all three GATA factors are capable of mediating transcriptional effects via a common erythroid consensus DNA-binding motif. Furthermore, GATA-2 and GATA-3, because of their distinct expression patterns and broader DNA recognition properties, may be involved in additional regulatory processes beyond those of GATA-1. The definition of an alternative GATA-2-GATA-3 consensus sequence may facilitate the identification of new target genes in the further elucidation of the roles that these transcription factors play during development.
GATA转录因子家族的成员,在其锌指DNA结合结构域内具有高度的氨基酸序列同一性,各自呈现出独特但又相互重叠的组织限制性表达模式。尽管GATA-1、-2和-3已被证明可识别源自红系细胞特异性基因调控元件的共有序列WGATAR(其中W表示A/T,R表示A/G),但此前尚未探讨过每个因子在结合偏好上可能存在的更细微差异。通过采用结合筛选和聚合酶链反应扩增方案以及随机寡核苷酸,我们确定了细菌表达的鸡GATA-1、-2和-3转录因子的结合位点特异性。虽然所有三种GATA因子都以高亲和力结合AGATAA红系共有基序,但第二个替代共有DNA序列AGATCTTA也能被GATA-2和GATA-3很好地识别,而GATA-1对其识别较差。这些研究表明,所有三种GATA因子都能够通过一个共同的红系共有DNA结合基序介导转录效应。此外,由于GATA-2和GATA-3具有独特的表达模式和更广泛的DNA识别特性,它们可能参与了GATA-1之外的其他调控过程。确定一个替代的GATA-2 - GATA-3共有序列可能有助于在进一步阐明这些转录因子在发育过程中所起作用时鉴定新的靶基因。