Mechanism of RIN1 Signaling in Neuronal Plasticity

RIN1 信号传导在神经元可塑性中的机制

• 批准号: 6910730
• 负责人: JOHN J. COLICELLI
• 金额: $ 28.57万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6910730
• 关键词: G protein; SDS polyacrylamide gel electrophoresis; allosteric site; biological signal transduction; confocal scanning microscopy; cytoskeleton; enzyme activity; laboratory mouse; learning; long term potentiation; mass spectrometry; memory; neural plasticity; neurons; phosphorylation; protein kinase; protein structure function; tissue /cell culture

DESCRIPTION (provided by applicant): The RIN1 protein is a RAS effector expressed predominantly in mature forebrain neurons. RIN1 stimulates ABL family tyrosine kinases and directs cytoskeletal remodeling. RIN1 null mutant mice show a striking increase in long term potentiation (LTP) and enhancement in memory (i.e. RIN1 normally inhibits learning). H-,K-, NRAS and ABL2 are also expressed in forebrain neurons and perform learning and memory functions. These studies provide critical insights into a tissue-specific RAS pathway that regulates neuronal plasticity (learning). Understanding RIN1 function may also have implications for neuropsychiatric disorders. RIN1 binds to ABL proteins. Moreover, RIN1 is unique as a direct ABL kinase activator. RAS appears to stimulate RIN1 activation of ABL2 and these three proteins (RAS, RIN1, ABL2) are found as a complex in vivo. These data demonstrate a physical and functional connection between RAS and ABL proteins. RIN1 promotes the ABL2 phosphorylation of CRKII and CRKL, adaptor proteins that coordinate cytoskeletal remodeling. The first aim of this proposal is to define the mechanism by which RIN1 stimulates ABL2 kinase activity. This may involve a substrate-specific enhancement (i.e. RIN1 provides a docking site for CRK proteins) or an allosteric function (i.e., RIN1 induces changes in the ABL2 kinase active site). Understanding the RIN1- mediated stimulation mechanism should expand opportunities for manipulating ABL function in learning, as well as in cell transformation. The second aim is to define signaling components used by RIN1 to promote cytoskeletal remodeling. RIN1 and ABL2 are complexed with CRKL in vivo. CRKII and CRKL reorganize the cytoskeleton through multiple SH2 and SH3 binding partners. Identification of RIN1/CRK(L) complex components will provide new insights into stimulus-induced and cell type specific remodeling. The third aim of this proposal is to evaluate the contribution of RIN1 to neuronal plasticity. RIN1 can coordinate cytoskeletal remodeling as well as compete with other RAS effectors. We will use cultured neurons and brain tissue to determine how neuronal stimulation engages the RAS-RIN1-ABL2-CRK(L) pathway and how activation of this pathway negatively regulates plasticity. Special focus will be placed on dendritic spine remodeling because the connection of this phenomenon to learning remains conjectural.

描述（由申请人提供）：RIN 1蛋白是一种RAS效应子，主要在成熟前脑神经元中表达。RIN 1刺激ABL家族酪氨酸激酶并指导细胞骨架重塑。RIN 1无效突变小鼠显示出长时程增强（LTP）的显著增加和记忆的增强（即RIN 1通常抑制学习）。H-、K-、NRAS和ABL 2也在前脑神经元中表达，并执行学习和记忆功能。这些研究为调节神经元可塑性（学习）的组织特异性RAS通路提供了重要见解。了解RIN 1功能也可能对神经精神疾病有影响。 RIN 1与ABL蛋白结合。此外，RIN 1作为直接ABL激酶激活剂是独特的。RAS似乎刺激ABL 2的RIN 1活化，并且这三种蛋白质（RAS、RIN 1、ABL 2）在体内被发现为复合物。这些数据表明RAS和ABL蛋白之间的物理和功能联系。RIN 1促进CRKII和CRKL的ABL 2磷酸化，CRKII和CRKL是协调细胞骨架重塑的衔接蛋白。 该建议的第一个目的是确定RIN 1刺激ABL 2激酶活性的机制。 这可能涉及底物特异性增强（即RIN 1为CRK蛋白提供对接位点）或变构功能（即，RIN 1诱导ABL 2激酶活性位点的变化）。了解RIN 1介导的刺激机制应该扩大在学习和细胞转化中操纵ABL功能的机会。 第二个目标是确定RIN 1用于促进细胞骨架重塑的信号传导组分。 RIN 1和ABL 2在体内与CRKL复合。CRKII和CRKL通过多个SH 2和SH 3结合配偶体重组细胞骨架。RIN 1/CRK（L）复合物组分的鉴定将为刺激诱导的和细胞类型特异性重塑提供新的见解。 该建议的第三个目的是评估RIN 1对神经元可塑性的贡献。RIN 1可以协调细胞骨架重塑以及与其他RAS效应物竞争。我们将使用培养的神经元和脑组织来确定神经元刺激如何参与RAS-RIN 1-ABL 2-CRK（L）通路以及该通路的激活如何负调节可塑性。将特别关注树突棘重塑，因为这种现象与学习的联系仍然是神经学的。