Chimaerins-receptors for diacylgly and phorbal esters

二酰基和佛巴酯的嵌合蛋白受体

基本信息

批准号：
7665264
负责人：
MARCELO G. KAZANIETZ
金额：
$ 5.65万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
1997
资助国家：
美国
起止时间：
1997-09-30 至 2013-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7665264
关键词：
1,2-diacylglycerol Actins Adhesions Affect Alleles Animal Model Binding Breast Breast Cancer Cell C-terminal Cancer Etiology Cell Cycle Progression Cell physiology Cyclin D1 Cytoskeleton DAG/PE-Binding Domain Data Diglycerides Disease Progression Down-Regulation EGF gene Epidermal Growth Factor Receptor Esters Etiology Family Funding GTPase-Activating Proteins Generations Goals Guanosine Triphosphate Guanosine Triphosphate Phosphohydrolases Heregulin Human Hydrolysis Isoenzymes Knock-in Mouse Knock-out Knockout Mice Laboratories Ligands Link Lipids Malignant - descriptor Malignant Neoplasms Mammary Neoplasms Mediating Methylation Modeling Monomeric GTP-Binding Proteins N-terminal Names Neoplasm Metastasis Neoplasms Nude Mice Pathway interactions Personal Satisfaction Phenotype Phorbol Esters Phospholipase C Phosphorylation Phosphorylation Site Phosphotyrosine Play Positioning Attribute Protein Binding Protein Family Protein Kinase C Protein Overexpression Protein-Serine-Threonine Kinases Proteins Public Health Receptor Activation Receptor Protein-Tyrosine Kinases Regulation Role Second Messenger Systems Signal Transduction Site Specimen Tertiary Protein Structure Tetradecanoylphorbol Acetate Therapeutic Translating Tumor Promoters Tumor Suppressor Proteins Work Xenograft procedure cell motility citrate carrier concept malignant breast neoplasm migration mouse model mutant novel phorbol ester receptor promoter receptor response second messenger src Homology Region 2 Domain tumor progression tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): This competing renewal focuses on the characterization of an intracellular receptor for the phorbol ester tumor promoters and the second messenger diacylglycerol (DAG), ¿2-chimaerin, and its relevance in the etiology of breast cancer. With the support of this RO1 we unambiguously established the concept of "divergence in DAG signaling", which implies that DAG and phorbol ester tumor promoters can trigger responses via direct activation of effectors that do not belong to the protein kinase C (PKC) family, considered until not so long ago the only intracellular receptors for DAG and phorbol esters. ¿2-chimaerin possesses 3 well-defined regions: a N-terminal SH2 domain of unknown function (present only in a2- and ¿2-chimaerins), a C1 domain (responsible for DAG and phorbol ester binding), and a C-terminal GTPase Activating Protein (GAP) domain that has the ability to accelerate the hydrolysis of GTP from the small G-protein Rac, leading to Rac inactivation. We established that ¿2-chimaerin is a direct effector of the EGF receptor via the DAG pathway, and that activation of ¿2-chimaerin serves as a "brake" that limits the activation of Rac in response to tyrosine kinase receptor stimulation. Moreover, we determined that in breast cancer cells ¿2-chimaerin negatively modulates Rac1-mediated responses, including actin cytoskeleton reorganization, migration, invasion, proliferation, cell cycle progression, and cyclin D1 induction in response to ErbB receptor ligands, including EGF and heregulin. Remarkably, preliminary studies revealed that ¿2-chimaerin is down-regulated in human breast cancer cells and specimens, suggesting a potential tumor suppressor role for this DAG-regulated Rac-GAP. As an extension of our previous work we now propose 4 aims. In Aim 1 we will determine the relevance of ¿-chimaerin in breast cancer progression using xenografts and also 1ith knock-out and knock-in mice for a hyperactive ¿2-chimaerin mutant (I130A allele). In Aim 2 we will analyze the expression of ¿2-chimaerin in a panel of human mammary tumors and their matched normal counterparts in order to validate our preliminary evidence that ¿2-chimaerin is down-regulated in breast cancer. We will also focus on promoter methylation as the potential cause for this down-regulation. In Aim 3 we will assess the regulation of ¿2-chimaerin activity and function by phosphorylation, as data revealed a PKC phosphorylation potentially modulates the Rac-GAP activity of ¿2-chimaerin. Lastly, in Aim 4 we will identify and validate potential proteins that interact with ¿2-chimaerin via the SH2 domain and determine the functional consequences of such interactons. The identification of a DAG/phorbol ester receptor unrelated to the PKC family that negatively regulates responses associated with the progression of breast cancer, and probably other neoplasias, not only has fundamental connotations in cancer signaling, but it may also reveal novel aspects of the etiology of cancer and have important therapeutic implications. PUBLIC HEALTH RELEVANCE: In this proposal we will characterize a receptor for the phorbol ester tumor promoters and the lipid second messenger diacylglycerol (DAG) named ¿2-chimaerin. We found that this protein negatively regulates important cellular functions involved in tumorigenesis and metastasis, and that it is down-regulated in breast cancer, suggesting a potential relationship with breast cancer etiology. This proposal will investigate the relevance of ¿2-chimaerin in breast cancer progression as well as key regulatory mechanisms that control its activation and function.

描述（由申请人提供）：这一竞争性更新的重点是佛波酯肿瘤促进剂和第二信使二酰甘油（DAG）的细胞内受体的表征，¿ 2-嵌合蛋白及其与乳腺癌病因学的相关性在该 RO1 的支持下，我们明确建立了“DAG 信号传导的分歧”的概念，这意味着 DAG 和佛波酯肿瘤启动子可以通过直接激活效应器来触发反应。不属于蛋白激酶 C (PKC) 家族，不久前该家族还被认为是 DAG 和佛波酯的唯一细胞内受体。 2-嵌合蛋白具有 3 个明确的区域：功能未知的 N 端 SH2 结构域（仅存在于 a2- 和 ¿2-嵌合蛋白中）、C1 结构域（负责 DAG 和佛波酯结合）和 C 端我们建立了 GTP 酶激活蛋白 (GAP) 结构域，能够加速小 G 蛋白 Rac 水解 GTP，从而导致 Rac 失活。那 2-chimaerin 是 EGF 受体通过 DAG 途径的直接效应物，并且激活 ¿ 2-嵌合蛋白充当“制动器”，限制 Rac 响应酪氨酸激酶受体刺激的激活此外，我们确定在乳腺癌细胞中 ¿ 2-chimaerin 负向调节 Rac1 介导的反应，包括肌动蛋白细胞骨架重组、迁移、侵袭、增殖、细胞周期进展和细胞周期蛋白 D1 诱导，以响应 ErbB 受体配体（包括 EGF 和heregulin）。 2-chimaerin 在人类乳腺癌细胞和样本中下调，表明这种 DAG 调节的 Rac-GAP 具有潜在的肿瘤抑制作用，作为我们之前工作的延伸，我们现在提出 4 个目标。的相关性-嵌合蛋白在乳腺癌进展中使用异种移植物以及第 1th 敲除和敲入小鼠以治疗过度活跃 ¿ 2-chimaerin 突变体（I130A 等位基因）在目标 2 中，我们将分析 ¿ 2-chimaerin 在一组人类乳腺肿瘤及其匹配的正常新生儿中进行研究，以验证我们的初步证据 ¿ 2-嵌合蛋白在乳腺癌中下调，我们还将关注启动子甲基化作为这种下调的潜在原因。 ¿ 2-嵌合蛋白的活性和功能通过磷酸化，数据显示 PKC 磷酸化可能调节 ¿ 的 Rac-GAP 活性最后，在目标 4 中，我们将鉴定并验证与 ¿ 相互作用的潜在蛋白质。 2-chimaerin 通过 SH2 结构域并确定此类相互作用的功能后果鉴定出与 PKC 家族无关的 DAG/佛波酯受体，该受体负向调节与乳腺癌以及可能其他肿瘤进展相关的反应。癌症信号传导的基本内涵，但它也可能揭示癌症病因学的新方面，并具有重要的治疗意义：在本提案中，我们将描述佛波醇的受体。酯类肿瘤促进剂和脂质第二信使二酰基甘油 (DAG) 命名为 ¿我们发现这种蛋白负向调节参与肿瘤发生和转移的重要细胞功能，并且它在乳腺癌中下调，表明与乳腺癌病因学的潜在关系。 2-嵌合蛋白在乳腺癌进展中的作用以及控制其激活和功能的关键调节机制。