Crossley M, Orkin S H
Division of Hematology-Oncology, Children's Hospital, Dana-Farber Cancer Institute, Boston, Massachusetts 02115.
J Biol Chem. 1994 Jun 17;269(24):16589-96.
GATA-1 is a zinc finger DNA-binding protein thought to be involved in the expression of the vast majority of erythroid specific genes. We have examined the phosphorylation of GATA-1 in murine erythroleukemia (MEL) cells and have mapped the sites of phosphorylation by overexpression of GATA-1 in monkey kidney COS cells. We show that GATA-1 is phosphorylated on 6 serines within its amino terminus in uninduced MEL cells and that a 7th site, serine 310, becomes phosphorylated after MEL cells are induced to differentiate by exposure to dimethyl sulfoxide. This site lies near the carboxyl boundary of the DNA-binding domain in a conserved region of the protein believed to be involved in DNA bending. Detailed analyses indicate, however, that phosphorylation at this site, or the other sites identified, does not significantly influence DNA-binding affinity or specificity, DNA bending, or transcriptional transactivation by GATA-1.
GATA-1是一种锌指DNA结合蛋白，被认为参与了绝大多数红系特异性基因的表达。我们检测了小鼠红白血病（MEL）细胞中GATA-1的磷酸化情况，并通过在猴肾COS细胞中过表达GATA-1来确定磷酸化位点。我们发现，在未诱导的MEL细胞中，GATA-1在其氨基末端的6个丝氨酸上发生磷酸化，而在MEL细胞经二甲基亚砜诱导分化后，第7个位点丝氨酸310也会发生磷酸化。该位点位于DNA结合结构域的羧基边界附近，在该蛋白的一个保守区域内，据信该区域参与DNA弯曲。然而，详细分析表明，该位点或其他已确定位点的磷酸化并不会显著影响GATA-1的DNA结合亲和力或特异性、DNA弯曲或转录激活。
