CELLULAR FUNCTION AND REGULATION OF ETS PROTEINS

ETS 蛋白质的细胞功能和调节

• 批准号: 3853512
• 负责人: T S PAPAS
• 金额: --
• 依托单位: DIVISION OF CANCER EPIDEMIOLOGY AND GENETICS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3853512
• 关键词: DNA binding protein; astrocytes; astrocytoma; calcium flux; carbachol; cell growth regulation; cellular oncology; flow cytometry; gene expression; human tissue; mitogens; oncoproteins; phosphatase inhibitor; phosphoproteins; phosphorylation; protein biosynthesis; protooncogene; stoichiometry; synchronous cell division; tissue /cell culture

Expression of the ETS proteins during the cell cycle has been examined in cells synchronized by centrifugal elutriation or mitotic block using the microtubule-destabilizing agent, nocodazole. Both methods reveal the presence of a hyperphosphorylated isoform of ETSI during the early mitotic phase of the cell cycle. This isoform exhibits a strong mobility shift in SDS-PAGE and has been observed during mitosis in each of four cell lines (three human T-cell lines and one human astrocytoma line) which express c-ETSI. This isoform is distinguishable from previously described phosphorylated isoforms of ETS1 and appears to arise due to multiple phosphorylations on serine in the domain of the protein encoded by exon 7 of the ETSI gene. Treatment of unsynchronized cells with the phosphatase inhibitor, okadaic acid, results in a stoichiometric shift of ETS1 to this hyperphosphorylated state, suggesting that cellular phosphatase activity is important for regulation of ETSI. The potential correlation of the different ETS1 phosphorylation states with functional activity of the protein in sequence-specific DNA binding is currently under investigation. Carbachol-induced stimulation of ETS1 phosphorylation in 132INI astrocytoma cells is also being studied; the relation to intracellular Ca++ levels and enzymes involved during this stimulation is being compared to the mitotic ETSI phosphorylation.

ETS蛋白在细胞周期中的表达已经在 通过离心淘洗或有丝分裂阻滞同步化的细胞， 微管去稳定剂诺考达唑。 这两种方法都揭示了 早期存在过度磷酸化的ETSI亚型， 细胞周期的有丝分裂期。 这种亚型表现出很强的流动性 在SDS-PAGE中观察到的偏移，并在四个细胞中的每一个的有丝分裂期间观察到。 细胞系（三种人T细胞系和一种人星形细胞瘤细胞系） 表达c-ETSI。 这种亚型与以前的亚型不同， 描述了ETS 1的磷酸化同种型，并且似乎是由于 编码蛋白质结构域中丝氨酸的多重磷酸化 ETSI基因的外显子7。 用以下处理非同步化细胞： 磷酸酶抑制剂冈田酸导致 ETS 1这种过度磷酸化状态，表明细胞 磷酸酶活性对于ETSI的调节是重要的。 的潜在 不同的ETS 1磷酸化状态与功能的相关性 该蛋白在序列特异性DNA结合中的活性目前被 在研究中 氨甲酰胆碱诱导的ETS 1刺激 132 INI星形细胞瘤细胞中的磷酸化也正在研究中; 与细胞内Ca++水平和参与此过程的酶的关系 将刺激与有丝分裂ETSI磷酸化进行比较。