The transcription factor GATA4 is activated by extracellular signal-regulated kinase 1-and 2-mediated phosphorylation of serine 105 in cardiomyocytes
The transcription factor GATA4 is activated by extracellular signal-regulated kinase 1-and 2-mediated phosphorylation of serine 105 in cardiomyocytes
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DOI：
10.1128/mcb.21.21.7460-7469.2001
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发表时间：
2001-11-01
影响因子：
5.3
通讯作者：
Molkentin, JD
中科院分区：
文献类型：
--
作者：
Liang, QR;Wiese, RJ;Molkentin, JD
含锌指的转录因子 GATA4 被认为是多种心脏表达基因的关键调节因子，也是响应肥大刺激的诱导基因表达的调节因子。在这里，我们证明 GATA4 本身通过直接磷酸化受到丝裂原激活蛋白激酶信号级联的调节。定点诱变和磷酸化特异性 GATA4 抗血清显示丝氨酸 105 是参与激动剂诱导的 GATA4 磷酸化的主要位点。用表达 MEK1 的激活腺病毒感染培养的心肌细胞，诱导 GATA4 中丝氨酸 105 的强烈磷酸化，而表达显性失活 MEK1 的腺病毒则阻断激动剂诱导的丝氨酸 105 磷酸化，表明细胞外信号调节激酶 (ERK) 是一种 GATA4 激酶。事实上，细菌纯化的 ERK2 蛋白在体外直接磷酸化纯化的 GATA4 丝氨酸 105。丝氨酸 105 的磷酸化增强了 GATA4 的转录效力，GATA4 对 U0126（MEK1 抑制剂）敏感，但对 SB202190（p38 抑制剂）不敏感。丝氨酸 105 的磷酸化也适度增强了细菌纯化的 GATA4 的 DNA 结合活性。最后，用表达 MEK1 的激活腺病毒诱导心肌细胞肥大，用显性失活表达 GATA4 的腺病毒阻断。这些结果表明 MEK1-ERK1/2 信号传导通过转录因子 GATA4 通过丝氨酸 105 的直接磷酸化来调节心肌细胞肥大生长，从而增强 DNA 结合和转录激活。
The zinc finger-containing transcription factor GATA4 has been implicated as a critical regulator of multiple cardiac-expressed genes as well as a regulator of inducible gene expression in response to hypertrophic stimulation. Here we demonstrate that GATA4 is itself regulated by the mitogen-activated protein kinase signaling cascade through direct phosphorylation. Site-directed mutagenesis and phospho-specific GATA4 antiserum revealed serine 105 as the primary site involved in agonist-induced phosphorylation of GATA4. Infection of cultured cardiomyocytes with an activated MEK1-expressing adenovirus induced robust phosphorylation of serine 105 in GATA4, while a dominant-negative MEK1-expressing adenovirus blocked agonist-induced phosphorylation of serine 105, implicating extracellular signal-regulated kinase (ERK) as a GATA4 kinase. Indeed, bacterially purified ERK2 protein directly phosphorylated purified GATA4 at serine 105 in vitro. Phosphorylation of serine 105 enhanced the transcriptional potency of GATA4, which was sensitive to U0126 (MEK1 inhibitor) but not SB202190 (p38 inhibitor). Phosphorylation of serine 105 also modestly enhanced the DNA binding activity of bacterially purified GATA4. Finally, induction of cardiomyocyte hypertrophy with an activated MEK1-expressing adenovirus was blocked with a dominant-negative GATA4-engrailed-expressing adenovirus. These results suggest a molecular pathway whereby MEK1-ERK1/2 signaling regulates cardiomyocyte hypertrophic growth through the transcription factor GATA4 by direct phosphorylation of serine 105, which enhances DNA binding and transcriptional activation.