Function of NudC, a Prolactin Regulated Gene

催乳素调控基因 NudC 的功能

• 批准号: 7032942
• 负责人: LI-YUAN YU-LEE
• 金额: $ 29.1万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-15 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7032942
• 关键词: RNA interference; biological signal transduction; cell cycle; cell growth regulation; cell proliferation; dynein ATPase; gene induction /repression; genetic regulation; hormone regulation /control mechanism; microscopy; microtubules; mitogens; phosphorylation; prolactin; regulatory gene; tissue /cell culture

DESCRIPTION (provided by applicant): The pituitary hormone prolactin (PRL) stimulates the growth and differentiation of many tissues and cell types. To understand a role of PRL in mitogenic signaling, we isolated a number of immediate early genes activated after PRL stimulation. One such gene, NudC, was cloned as an early growth response gene. Genetic, biochemical and cellular studies show that NudC associates with the microtubule (MT)-dependent dynein/dynactin motor complex that mediates many mitotic processes. Our studies suggest that NudC plays multiple roles in mitosis (nuclear division) and cytokinesis (cytoplasmic division). We showed that altering NudC levels by either small interference RNA (siRNA)-mediated gene silencing or adenovirus-mediated overexpression resulted in defects in cytokinesis, as reflected by an increase in the number of multinucleated cells and cells with persistent intercellular connections. MTs in the midzone and midbody matrix appeared disorganized, providing a possible clue on a cytokinesis defect. In addition, we show that NudC is a mitotic phosphoprotein and it interacts with the mitotic kinase polo-like kinase 1 (Plkl), suggesting that NudC phosphorylation may affect NudC functions during mitosis. We hypothesize that a precise level and phosphorylation state of NudC are required for mitotic progression and completion of cytokinesis, and that NudC functions by regulating the dynein/dynactin complex and MT dynamics during mitosis and cytokinesis. To delineate NudC functions in mitogenic signaling, we propose to 1) Determine NudC function in mitosis and cytokinesis by analyzing how changes in NudC levels and phosphorylation state affect mitosis progression and completion of cytokinesis, and to 2) Analyze regulation of dynein/dynactin by NudC by addressing how NudC regulates dynein complex stability and MT dynamics. These studies should contribute to a fundamental understanding of the mechanisms of PRL-mediated mitogenic signaling.

描述(申请人提供)：垂体激素催乳素(PRL)刺激许多组织和细胞类型的生长和分化。为了了解PRL在有丝分裂信号中的作用，我们分离了一些PRL刺激后激活的即刻早期基因。其中一个名为nudC的基因被克隆为早期生长反应基因。遗传学、生物化学和细胞学研究表明，nudC与微管依赖的dynein/dynactin运动复合体有关，该复合体介导了许多有丝分裂过程。我们的研究表明，nudC在有丝分裂(核分裂)和胞质分裂(细胞质分裂)中发挥多种作用。我们发现，通过小干扰RNA(SiRNA)介导的基因沉默或腺病毒介导的过度表达来改变nudC水平会导致胞质分裂缺陷，这反映在多核细胞和具有持续细胞间连接的细胞的数量增加。中区和中体基质中的MTS看起来杂乱无章，为细胞质缺陷提供了可能的线索。此外，我们还发现，nudC是一种有丝分裂的磷酸蛋白，它与有丝分裂激酶Polo-like kinase1(Plk1)相互作用，提示在有丝分裂过程中，nudC的磷酸化可能影响nudC的功能。我们假设，有丝分裂的进行和胞质分裂的完成需要一个精确的nudC水平和磷酸化状态，并且在有丝分裂和胞质分裂过程中，nudC通过调节dynein/dynactin复合体和MT的动力学来发挥作用。为了阐明nudC在有丝分裂信号中的功能，我们建议1)通过分析nudC水平和磷酸化状态的变化如何影响有丝分裂进程和细胞质分裂的完成，来确定nudC在有丝分裂和胞质分裂中的作用；2)通过nudC如何调节dynein复合体的稳定性和MT动力学来分析nudC对dynein/dynactin的调节。这些研究应该有助于从根本上理解PRL介导的有丝分裂信号的机制。