P13K/AKT crosstalk with ER-signaling and cell survival

P13K/AKT 串扰与 ER 信号传导和细胞存活

• 批准号: 6993557
• 负责人: Matthew E. Burow
• 金额: $ 29万
• 依托单位: TULANE UNIVERSITY OF LOUISIANA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-18 至 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6993557
• 关键词: SDS polyacrylamide gel electrophoresis; autoradiography; biological signal transduction; cell line; estrogen receptors; flow cytometry; gene expression; genetic transcription; hormone sensitivity /resistance; northern blottings; phosphorylation; protein kinase; protein structure function; tissue /cell culture; transfection

DESCRIPTION (provided by applicant): The primary long-term objective of this research is to understand the role of AKT-signaling cross-talk with the estrogen receptor (ER) in the control of cell survival and in the development of anti-estrogen resistance. We hypothesize that the AKT pathway functions to target and phosphorylate the p160 coactivator GRIP and ER proteins leading to regulation of CoA-recruitment, receptor-activation and gene expression. We further hypothesize that convergence of the AKT and estrogen signaling at the ER-CoA-transcriptional level is critical in the regulation of cell survival and influences selective estrogen receptor modulator (SERM) activity in hormone dependent cell systems such as breast carcinoma. The Specific Aims are proposed to 1) Determine the mechanisms of AKT-ER cross-talk by examining specific targeting, phosphorylation and activation of ER-AF2 and/or the p160 CoA GRIP by AKT and 2) Determine the physiological relevance of this cross-talk by examining effects of AKT-ER-CoA on the regulation of endogenous estrogen-responsive genes, alteration of SERM-activity and gene expression, and long-term cell survival. Specific Aim #1, To determine the role of AKT targeting and phosphorylation of ER-AF2 as a mechanism for cross-talk. We propose to determine if the ER-AF2 targeting occurs through direct phosphorylation by AKT and the role of specific phosphorylation sites in AKT-ER cross-talk. Specific Aim #2, To implicate AKT regulation of p160 coactivator-(GRIP) phosphorylation as a mechanism for activation of and recruitment to estrogen receptors. Studies will determine if AKT phosphorylates and activates GRIP though specific targeting of the GRIP-NRID (nuclear receptor interaction domain) or GRIP-AD2 (activation domain-2) as mechanisms for AKT regulation of GRIP in control of ER transcription. Specific Aim #3, to determine the requirement for GRIP phosphorylation/function in AKT-mediated regulation of ER-dependent cell survival, gene expression and SERM activity. In this aim, we will determine the role for specific AKT induced ER-CoA recruitment/activation in the regulation of cell survival gene expression (Bcl-2) and the influence of AKT-ER-CoA cross-talk on SERM activity. These studies will also determine if the mechanisms for AKT-phosphorylation of ER or GRIP from above are critical in the AKT-ER mediated regulation of cell survival. It is expected as a whole that this proposal will establish the mechanisms used by the investigator3K-AKT cascade to target the ER and the subsequent components of the ER transcription complex required for potentiation of activity by this pathway. This cross-talk and the mechanisms identified will be used to establish the biological relevancy of the pathway in terms of cell survival and altered SERM activity.

描述（由申请人提供）：这项研究的主要长期目标是了解Akt信号的串扰与雌激素受体（ER）在控制细胞存活和抗雌激素耐药性发展中的作用。我们假设AKT途径的功能可以靶向和磷酸化P160共激活剂握把和ER蛋白，从而导致COA摄取，受体激活和基因表达的调节。我们进一步假设，在ER-COA-转录水平上AKT和雌激素信号的收敛对于调节细胞存活至关重要，并且影响乳腺癌等激素依赖性细胞系统中选择性雌激素受体调节剂（SERM）活性。提出具体目的是为1）通过检查Akt-er-af2和/或p160 coA抓地力的特定靶向，磷酸化和激活Akt和2）确定AKT-ER-ACT和/或2）确定这种跨语的生理相关性来确定AKT-ER交叉讲话的机制。表达和长期细胞存活。具体目的＃1，确定Akt靶向ER-AF2作为交叉言论机制的作用。我们建议确定ER-AF2靶向是否是通过AKT直接磷酸化以及特定磷酸化位点在Akt-ER串扰中的作用而发生的。具体目的＃2，暗示了P160共激活剂（Grip）磷酸化的AKT调节，作为激活和募集到雌激素受体的机制。研究将确定AKT磷酸化并激活Grip-NRID（核受体相互作用域）或Grip-AD2（激活结构域-2）的特定靶向，作为AKT调节ER转录控制的机制。具体目的＃3，以确定AKT介导的ER依赖性细胞存活，基因表达和SERM活性的调节中握持磷酸化/功能的需求。在此目标中，我们将确定特定AKT诱导的ER-COA募集/激活在调节细胞存活基因表达（BCL-2）和AKT-ER-COA串扰对Serm活性的影响。这些研究还将确定从上面的Akt磷酸化或抓地力的Akt磷酸化机制对于AKT-ER介导的细胞存活调节至关重要。总体上可以预期，该提案将建立研究器3K-Akt级联对靶向ER的机制以及该途径增强活动所需的ER转录复合物的随后成分。这种串扰和所确定的机制将用于在细胞存活和改变Serm活性方面建立途径的生物学相关性。