PACAP: A NOVEL PROAPOPTOTIC CASPASE ADAPTER PROTEIN

PACAP：一种新型促凋亡胱天蛋白酶适配器蛋白

• 批准号: 6531744
• 负责人: EMANUELA M BONFOCO
• 金额: $ 22.8万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-30 至 2004-04-05
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6531744
• 关键词: B lymphocyte; apoptosis; binding proteins; biological signal transduction; cysteine endopeptidases; enzyme mechanism; laboratory mouse; nuclear factor kappa beta; protein protein interaction

DESCRIPTION (provided by applicant): Apoptosis or programmed cell death is a crucial process for the development and maintenance of a functional immune system. Apoptosis depends upon a family of cysteine proteases (caspases) whose activation is subject to both negative and positive regulatory mechanisms. Recently we discovered and have partially characterized a novel pro-apoptotic caspase adaptor protein (PACAP) that interacts with two initiator caspases, caspase-2 and -9. To date we have observed the following: when PACAP is overexpressed in cell lines, apoptosis is induced and the NF-kappaB pathway is activated. Support for a role for PACAP as a regulatory protein derives from the observations that the transcription of endogenously expressed PACAP in primary human B cells is rapidly and dramatically down regulated after B-cell activation and upregulated during apoptosis. Moreover PACAP forms complexes with Bcl10, a protein linked to NF-kappaB activation in some cell types and to a variety of human malignancies. Thus it is our hypothesis that PACAP may serve to direct extracellular signals to either casp-2 or -9 apoptotic pathways and may further regulate other intracellular pathways activated during the apoptotic pathway. To test this hypothesis we propose three Specific Aims that utilize molecular and cellular biological, immunological and biochemical approaches to further define the properties of PACAP in the context of physiologically relevant cellular models where casp-2 and caspase-9 play essential roles in cell death pathways. The proposed Specific Aims are: 1. To provide a detailed biochemical analysis of PACAP interactions; 2. To provide a comprehensive definition of the components that comprise the PACAP apoptotic signaling pathway; and 3. To provide further identification of other potential regulators of PACAP mediated intracellular signaling with an emphasis on the NF-kappaB pathway. The proposed studies are designed to provide fundamental information about this newly discovered protein that serves as a regulator of apoptotic pathways linked to both caspases-2 and-9. The long term goals of the proposed studies are to enhance our abilities to understand basic processes leading to human diseases linked to a dysfunctional immune system.

描述（由申请人提供）：细胞凋亡或程序性细胞死亡是功能性免疫系统发育和维持的关键过程。细胞凋亡取决于半胱氨酸蛋白酶（半胱天冬酶）家族，其激活受到负调节机制和正调节机制的影响。最近，我们发现并部分表征了一种新型促凋亡 caspase 衔接蛋白 (PACAP)，它与两种起始 caspase（caspase-2 和 -9）相互作用。迄今为止，我们观察到以下情况：当 PACAP 在细胞系中过表达时，会诱导细胞凋亡并激活 NF-κB 途径。 PACAP 作为调节蛋白的作用的支持源自以下观察：原代人 B 细胞中内源表达的 PACAP 的转录在 B 细胞激活后迅速而显着下调，并在细胞凋亡过程中上调。此外，PACAP 与 Bcl10 形成复合物，Bcl10 是一种与某些细胞类型和多种人类恶性肿瘤中 NF-kappaB 激活相关的蛋白质。因此，我们假设 PACAP 可能将细胞外信号引导至 casp-2 或 -9 凋亡途径，并可能进一步调节凋亡途径期间激活的其他细胞内途径。为了检验这一假设，我们提出了三个具体目标，利用分子和细胞生物学、免疫学和生化方法，在生理相关细胞模型的背景下进一步定义 PACAP 的特性，其中 casp-2 和 caspase-9 在细胞死亡途径中发挥重要作用。拟议的具体目标是： 1. 提供 PACAP 相互作用的详细生化分析； 2. 提供PACAP凋亡信号通路组成部分的全面定义； 3. 进一步鉴定 PACAP 介导的细胞内信号传导的其他潜在调节因子，重点是 NF-kappaB 通路。 拟议的研究旨在提供有关这种新发现的蛋白质的基本信息，该蛋白质充当与 caspase-2 和 caspase-9 相关的细胞凋亡途径的调节剂。拟议研究的长期目标是增强我们理解导致与免疫系统功能失调相关的人类疾病的基本过程的能力。