RGS14 integration of Gi/o and rap1/2 signaling pathways

超出所提供的空间。 神经递质和激素依赖于G蛋白对靶细胞发挥作用。与此相反，生长因子酪氨酸激酶受体募集级联连接的信号传导蛋白，包括ras样GTP酶，以调节细胞生长和分化。最近令人信服的证据表明，其他新的信号蛋白，包括某些G_。蛋白质信号传导（RGS蛋白）在多个水平整合G蛋白和ras超家族导向的通路。RGS蛋白是高度多样的多功能蛋白，其直接与G蛋白结合以调节其功能。RGSI 4含有我们和其他人已经显示与活性Gcd/o-GTP（RGS结构域）、非活性Gcd/o-GDP（GoLoco结构域）以及ras样GTP酶rapl和rap 2（RID结构域）相互作用的结构域（RGS、GoLoco和RID结构域）。宿主细胞中rapl/2途径的激活刺激MAPK/Erk激酶信号传导和神经元分化。RGS 14作为Gai和Gao信号传导的双重调节剂的作用尚不清楚。此外，RGS 14、Gcd/o和rapl/2如何相互作用以调节彼此的功能，以及在调节这些相互作用和相关的细胞反应中涉及什么样的细胞机制尚不清楚。我们的初步研究表明，RGS 14是磷酸化的激酶参与G蛋白和说唱信号。我们的假设是RGS 14是G蛋白（Ged/o）和rap-directed信号通路的整合者，刺激启动的磷酸化调节RGS 14与Ged和rap-directed信号通路的相互作用、亚细胞定位及其信号功能。利用现代分子、细胞和生物化学方法，具体目标将是：1。确定RGS I4作为膜中受体和God和Go信号传导的双功能调节剂的作用。2.定义调节RGS 14膜募集和附着、亚细胞定位以及与宿主B35细胞中mChoR、Gczi/o和rapl/2的α-Sassociati 0 n的细胞和生化机制。3.定义调节细胞中RGS 14磷酸化的细胞机制，以及磷酸化在体外RGS 14与mChoR/Gi/o和rapt/2相互作用中的作用，以及B35细胞中的相关信号通路。4.确定B35细胞中过表达RGSI 4或消除天然RGS 14对mChoR/GI/o和rapl/2定向信号事件和细胞反应的影响。影响：这些研究将确定RGS蛋白以前未被认识的细胞信号作用，并提供重要信息的新机制之间的G蛋白信号通路和rap/MAP激酶信号通路的串扰。这些研究结果将阐明我们对G蛋白/RGS蛋白信号传导复杂性的理解，并确定潜在的治疗干预新靶点。网站（==

EXCEED THE SPACE PROVIDED. Neurotransmitters and hormones rely upon G proteins to exert their effects on target cells. In contrast, growth factor tyrosine kinase receptors recruit a cascade of linked signaling proteins including ras-like GTPases to regulate cell growth and differentiation. Recent compelling evidence indicates that additional novel signaling proteins, including certain regulators of G_. protein signaling (RGS proteins) integrate G protein and ras superfamily-directed pathways at many levels. RGS proteins are highly diverse, multifunctional proteins that bind directly to G proteins to regulate their functions. RGSI4 contains domains (RGS, GoLoco and RID domains) that we and others have shown to interact with active Gcd/o-GTP (RGS domain), inactive Gcd/o-GDP (GoLoco domain) and with the ras-like GTPases rapl and rap2 (RID domain). Activation of rapl/2 pathways in host cells stimulates MAPK/Erk kinase signaling and neuronal differentiation. Roles for RGS14 as a dual regulator of Gai and Gao signaling are not known. Furthermore, how RGS14, Gcd/o and rapl/2 interact to regulate one anothers functions, and what cellular mechanisms are involved in regulating these interactions and linked cellular responses is not known. Our preliminary studies indicate that RGS14 is phosphorylated by kinases involved in G protein and rap signaling. Our hypothesis is that RGS14 is an integrator of G protein (Ged/o) and rap-directed signaling pathways, and that stimulus-initiated phosphorylation regulates RGS 14 interactions with G_ and rap, its subeellular localization, and its signaling functions. Using modern molecular, cellular and biochemical approaches, the specific aims will be to: 1. Determine roles for RGS I4 as a bifunctional regulator of receptor and God and G(_o signaling in membranes. 2. Define cellular and biochemical mechanisms that regulate RGS 14 membrane recruitment and attachment, subcellular localization, and a-Ssociati0n with mChoR, Gczi/o, and rapl/2 in host B35 cells. 3. Define cellular mechanisms for regulating RGS14 phosphorylation in cells, and roles for phosphorylation on RGS14 interactions with mChoR/Gi/o and rapt/2 in vitro, and linked signaling pathways in B35 cells. 4. Determine the effects of overexpressing RGSI4 or eliminating native RGS14 in B35 cells on mChoR/Gi/o and rapl/2- directed signaling events and cellular responses. Impact: These studies will identify previously unrecognized cell signaling roles for RGS proteins, and provide important information about novel mechanisms for cross-talk between G protein signaling pathways and rap/MAPkinase signaling pathways. Findings from these studies will clarify our understanding of the complexity of G protein/RGS protein signaling, and identify potential new targets for therapeutic intervention. PERFORMANCESITE( ========================================Section End===========================================