Angiotensin II-inducible platelet-derived growth factor-D transcription requires specific ser/thr residues in the second zinc finger region of Sp1
Angiotensin II-inducible platelet-derived growth factor-D transcription requires specific ser/thr residues in the second zinc finger region of Sp1
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DOI：
10.1161/circresaha.107.167395
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发表时间：
2008-02-29
影响因子：
20.1
通讯作者：
Khachigian, Levon M.
中科院分区：
文献类型：
--
作者：
Tan, Nicole Y.;Midgley, Valerie C.;Khachigian, Levon M.
SP1是第一个被发现和克隆的转录因子，它通过多种机制调节基因表达，包括蛋白质-DNA直接相互作用、蛋白质-蛋白质相互作用、染色质重塑和维持无甲基化的CpG岛。SP1本身受到不同水平的调节，例如，受糖基化、乙酰化和非典型蛋白激酶C-Zeta等激酶的磷酸化的调节。虽然Sp1控制着许多基因的基础调控和诱导调控，但对其功能的翻译后调控过程及其与病理学的相关性尚不清楚。在这里，我们使用了各种方法来鉴定Sp1锌指结构域中的3个氨基酸(Thr668、Ser670和Thr681)，它们被PKC-Zeta修饰，并产生了识别PKC-Zeta磷酸化形式的新型抗肽抗体。血管紧张素II通过血管紧张素II 1型受体激活PKC-Zeta磷酸化(Thr410)，刺激Sp1磷酸化，增加Sp1与血小板衍生生长因子-D启动子的结合。Sp1的3个残基(Thr668、Ser670和Thr681)都是血管紧张素II激活Sp1依赖的血小板衍生生长因子-D所必需的。免疫组织化学分析显示，磷酸化的Sp1在人动脉粥样硬化斑块的平滑肌细胞中表达，并与血小板衍生生长因子-D一起在损伤的大鼠颈动脉壁的平滑肌细胞中动态表达。这项研究为控制PKC-Zeta-磷酸-Sp1轴和血管紧张素II诱导基因表达的调控机制提供了新的见解。
Sp1, the first identified and cloned transcription factor, regulates gene expression via multiple mechanisms including direct protein-DNA interactions, protein-protein interactions, chromatin remodeling, and maintenance of methylation-free CpG islands. Sp1 is itself regulated at different levels, for example, by glycosylation, acetylation, and phosphorylation by kinases such as the atypical protein kinase C-zeta. Although Sp1 controls the basal and inducible regulation of many genes, the posttranslational processes regulating its function and their relevance to pathology are not well understood. Here we have used a variety of approaches to identify 3 amino acids (Thr668, Ser670, and Thr681) in the zinc finger domain of Sp1 that are modified by PKC-zeta and have generated novel anti-peptide antibodies recognizing the PKC-zeta-phosphorylated form of Sp1. Angiotensin II, which activates PKC-zeta phosphorylation (at Thr410) via the angiotensin II type 1 receptor, stimulates Sp1 phosphorylation and increases Sp1 binding to the platelet-derived growth factor-D promoter. All 3 residues in Sp1 (Thr668, Ser670, and Thr681) are required for Sp1-dependent platelet-derived growth factor-D activation in response to angiotensin II. Immunohistochemical analysis revealed that phosphorylated Sp1 is expressed in smooth muscle cells of human atherosclerotic plaques and is dynamically expressed together with platelet-derived growth factor-D in smooth muscle cells of the injured rat carotid artery wall. This study provides new insights into the regulatory mechanisms controlling the PKC-zeta-phospho-Sp1 axis and angiotensin II-inducible gene expression.