Investigating the biochemical and oncogenic properties of the Ras GTPase RIT1

项目摘要/摘要 RIT1是Ras家族中GTP酶家族的一员，它通过紧密地 受控信令网络。RIT1最近被描述为肺腺癌的致癌驱动因素 和髓系恶性肿瘤。尽管RIT1突变在癌症中的作用正在显现，但RIT1仍然是一个很差的 研究RAS GTP酶家族的成员。识别和表征RIT1的可能有助于 对于RIT1病的发病机制，我们进行了基于质谱学的筛查，确定了直接的 与主轴组件检查点(SAC)的组件连接，这是正常运行所必需的关键路径 有丝分裂过程中的染色体分离。对这种新的相互作用的表征揭示了突变体RIT1 通过抑制SAC促进非整倍体。尽管我们进行了初步评估，但进一步的分析是 需要了解这种相互作用的生理功能和SAC失调的贡献 RIT1致癌性。这项建议的目的是评估生物化学和致癌特性。 与SAC抑制相关的RIT1。其具体目的是：1)询问生理功能 和RIT1-SAC相互作用的调节以及2)检测RIT1介导的分子决定因素 致癌性。目标1将使用生化、结构和细胞生物学方法来评估 RIT1-SAC相互作用的调节，其结构特征，及其功能后果 主要的功能增益和功能损失单元模型。Aim 2将专注于一组正在进行的RIT1小鼠模型 A)评估RIT1-SAC相互作用对RIT1致瘤性的贡献和b)确定继发性 导致RIT1驱动的肿瘤发展的遗传损伤。拟议中的研究将有所帮助 阐明RIT1介导的肿瘤发生机制，以确定可能存在的易感性 探索了治疗策略的发展。 本提案中描述的研究策略将在弗兰克·麦考密克博士的实验室中进行 加州大学海伦·迪勒家庭综合癌症中心。奖学金培训计划纳入了专业人员 和职业发展活动，目的是1)增强我在生物化学和癌症方面的技术技能 生物学，2)提高我的沟通能力，3)发展有效的教学和指导技能，以及4) 为我的博士后培训职位做准备。完成这些目标将提供经验和 开始独立研究事业以继续研究分子所需的专业知识 促进癌症发展的信号转导通路失调的潜在机制 和疾病的进展。

Project Summary/Abstract RIT1 is a member of the Ras family of GTPases that direct broad cellular physiological responses through tightly controlled signaling networks. RIT1 has been recently described as an oncogenic driver of lung adenocarcinoma and myeloid malignancies. Despite the emerging role of RIT1 mutations in cancer, RIT1 remains a poorly studied member of the Ras GTPase family. To identify and characterize properties of RIT1 that may contribute to the pathogenesis of RIT1 disease, we performed a mass spectrometry-based screen that identified a direct link with components of the spindle assembly checkpoint (SAC), a critical pathway necessary for proper chromosome segregation during mitosis. Characterization of this novel interaction has revealed that mutant RIT1 promotes aneuploidy by suppressing the SAC. Despite our preliminary evaluation, further analyses are required to understand the physiological function of this interaction and the contribution of SAC dysregulation to RIT1 oncogenicity. The objective of this proposal is to evaluate the biochemical and oncogenic properties of RIT1 associated with SAC suppression. The specific aims are to 1) interrogate the physiological function and regulation of the RIT1-SAC interaction and 2) examine the molecular determinants of RIT1-mediated oncogenicity. Aim 1 will be achieved using biochemical, structural, and cell biological approaches to assess the regulation of the RIT1-SAC interaction, its structural characteristics, and its functional consequences using primary gain-of-function and loss-of-function cell models. Aim 2 will focus on a set of ongoing RIT1 mouse model studies to a) assess the contribution of the RIT1-SAC interaction to RIT1 oncogenicity and b) identify secondary genetic lesions that contribute to the development of RIT1-driven tumors. The proposed research will help elucidate the mechanism of RIT1-mediated tumorigenesis in order to identify potential vulnerabilities that can be explored for the development of therapeutic strategies. The research strategy described in this proposal will be conducted in the lab of Dr. Frank McCormick at the UCSF Helen Diller Family Comprehensive Cancer Center. The fellowship training plan incorporates professional and career development activities aimed at 1) building upon my technical skillset in biochemistry and cancer biology, 2) improving my communication skills, 3) developing effective teaching and mentoring skills, and 4) preparing me for a postdoctoral training position. Completion of these goals would provide the experience and expertise necessary to embark on an independent research career to continue investigating the molecular mechanisms underlying the dysregulation of signal transduction pathways that contribute to cancer development and disease progression.