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G protein signal integration by multifunctional proteins

多功能蛋白的 G 蛋白信号整合

基本信息

批准号：
7054061
负责人：
T KENDALL HARDEN
金额：
$ 125.14万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-04-10 至 2008-03-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): G protein-mediated signaling underlies the action of many growth factors, hormones, and neurotransmitters. Although initially conceived as linear and unidirectional, many G protein-related cell signaling pathways now are known to converge (and diverge) at many levels. For example, members of the large family of RGS proteins exhibit multiple biochemical activities in addition to their signature capacity to promote G-alpha-mediated GTP hydrolysis. This program project (PPG) applies a multidisciplinary approach to gain mechanistic and structural insight into important examples of multifunctional proteins in G protein signaling. We have assembled investigators with expertise in cancer biology (Der), in signaling in yeast (Dohlman), and in the molecular pharmacology/biochemistry (Harden), molecular biology/bioinformatics (Siderovski), and structure (Sondek) of G protein signaling. A Protein Core will play a central role in the PPG by facilitating high-throughput cloning, expression, purification, and biophysical characterization of proteins. The mechanism(s) of R7-family RGS proteins in "upstream" regulation of receptor/G protein interaction and cross-talk among heterotrimeric G proteins will be determined in Project I through studies with mammalian and C. elegans proteins. The multifunctional nature of the newly identified PLC-epsilon isozyme will be delineated in Project II through studies identifying interactors for the N-terminal RasGEF and C-terminal Ras-association domains, the role of PLC-epsilon in Ras-promoted cell transformation, and the domain(s) in PLC-epsilon that interacts with G-alpha-subunits. Project III will focus on the yeast protein Sst2, which was the first RGS protein discovered, and which contains an N-terminal DEP domain of unknown function also found in the mammalian R7-family RGS proteins studied in Projects I and IV. Yeast two-hybrid screens have identified proteins that bind the Sst2 N-terminal domain, and which activate the stress response signal. The domains of Sst2 responsible for G protein effector activity will be defined, as will the mechanism(s) of stress response signaling. Project IV will establish the structural basis for several functional interactions mediating cross-talk in G protein signaling by solving the structures of the beta5-R7 dimer and the GoLoco domain of R12-family RGS proteins, which has been shown to inhibit GDP release by G-alpha-i-subunits. This PPG will provide major new mechanistic insights into the molecular complexities that function across G protein signaling pathways and should illuminate new drug targets within fundamental processes that underlie diseases as diverse as cancer, heart disease, and mental disorders.

描述（由申请人提供）：G 蛋白介导的信号传导是许多生长因子、激素和神经递质的作用。虽然最初被认为是线性和单向的、许多G蛋白相关的细胞现在已知信号通路在许多层面上会聚（和发散）。为了例如，RGS 蛋白大家族的成员表现出多种生化活动除了其标志性的促进能力 G-α 介导的 GTP 水解。该计划项目（PPG）应用了多学科方法来获得机械和结构的洞察力 G 蛋白信号转导中多功能蛋白的重要例子。我们有聚集了具有癌症生物学（Der）、信号传导方面专业知识的研究人员酵母（Dohlman），以及分子药理学/生物化学（Harden）， G 的分子生物学/生物信息学 (Siderovski) 和结构 (Sondek) 蛋白质信号传导。蛋白质核心将在 PPG 中发挥核心作用促进高通量克隆、表达、纯化和生物物理蛋白质的表征。 R7家族RGS蛋白的作用机制受体/G蛋白相互作用和串扰的“上游”调节异源三聚体 G 蛋白将在项目 I 中通过研究来确定哺乳动物和线虫蛋白质。新产品的多功能性已确定的 PLC-ε 同工酶将在项目 II 中通过研究进行描述识别 N 端 RasGEF 和 C 端的相互作用子 Ras 关联域，PLC-epsilon 在 Ras 促进细胞中的作用变换，以及 PLC-epsilon 中与交互的域 G-α-亚基。项目 III 将重点关注酵母蛋白 Sst2，该蛋白是第一个被发现的 RGS 蛋白，包含 N 端 DEP 结构域在所研究的哺乳动物 R7 家族 RGS 蛋白中也发现了未知功能在项目 I 和 IV 中。酵母双杂交筛选已鉴定出以下蛋白质结合 Sst2 N 末端结构域，激活应激反应信号。负责 G 蛋白效应活性的 Sst2 结构域是定义，应激反应信号传导机制也将如此。项目四将建立多种功能相互作用的结构基础通过解析 beta5-R7 的结构来解决 G 蛋白信号传导中的串扰二聚体和 R12 家族 RGS 蛋白的 GoLoco 结构域，已被证明抑制 G-α-i-亚基释放 GDP。该 PPG 将提供重大新对跨 G 发挥作用的分子复杂性的机制见解蛋白质信号通路，并应阐明其中的新药物靶点癌症、心脏病等多种疾病的基本过程疾病和精神障碍。

项目成果

期刊论文数量（21）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Type III effector activation via nucleotide binding, phosphorylation, and host target interaction.

DOI：
10.1371/journal.ppat.0030048
发表时间：
2007-03
期刊：
PLOS PATHOGENS
影响因子：
6.7
作者：
Desveaux, Darrell;Singer, Alex U;Wu, Ai-Jiuan;McNulty, Brian C;Musselwhite, Laura;Nimchuk, Zachary;Sondek, John;Dangl, Jeffery L
通讯作者：
Dangl, Jeffery L

The R6A-1 peptide binds to switch II of Galphai1 but is not a GDP-dissociation inhibitor.

R6A-1 肽与 Galphai1 的开关 II 结合，但不是 GDP 解离抑制剂。