The mechanism of cell size regulation by polycystins

多囊蛋白调节细胞大小的机制

• 批准号: 10609393
• 负责人: Qian Chen
• 金额: $ 31.34万
• 依托单位: UNIVERSITY OF TOLEDO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-15 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10609393
• 关键词: Actin-Binding Protein; Actins; Actomyosin; Autosomal Dominant Polycystic Kidney; Biomass; Calcineurin; Calcium; Calcium Signaling; Calcium Spikes; Calmodulin; Cell Cycle; Cell Proliferation; Cell Separation; Cell Size; Cell division; Cell membrane; Cell physiology; Cells; Collaborations; Cytokinesis; Cytoskeleton; Endocytosis; Environment; Evolution; Family; Fission Yeast; Genes; Genetic Diseases; Genetic Screening; Growth; Human; Human Genetics; Image; In Vitro; Intracellular Transport; Ion Channel; Ions; Kidney Diseases; Lead; Lipids; Mediating; Michigan; Microfilaments; Microfluidics; Modeling; Molecular; Morphogenesis; Mutation; Myosin Type I; Myosin Type V; Osmosis; Osmotic Pressure; Pathway interactions; Pattern; Permeability; Phosphotransferases; Play; Polycystic Kidney Diseases; Process; Quantitative Microscopy; Regulation; Regulation of Cell Size; Reproducibility; Role; Signal Pathway; Signaling Molecule; Stimulus; Structure; Techniques; Tennessee; Testing; Universities; Work; Yeasts; autosome; cell growth; constriction; daughter cell; driving force; imaging modality; innovation; loss of function mutation; mechanical force; mechanical signal; mechanotransduction; model organism; multidisciplinary; novel; patch clamp; permissiveness; public health relevance; reconstitution; response; synergism

The mechanism of mechanosensing by polycystins during cell growth Cytokinesis is the last stage of cell division when two daughter cells separate, but it is equally important for the transition to cell growth including cell size expansion. The mechanism regulating such a transition is poorly understood. We identified the role of calcium and the polycystin channel Pkd2p in this process while studying cytokinesis of the model organism fission yeast. Pkd2p is essential to regulate the cell size and it mediates calcium influx. Polycystins are evolutionally conserved ion channels. Loss of function mutations of human polycystins lead to the genetic disorder, Autosomal Polycystic Kidney Disorder (ADPKD). The cellular function of this highly conserved family of channels is not well understood. This study will determine how Pkd2p and calcium regulate the transition to cell growth. Aim 1. Determine how the Hippo signaling pathways regulate Pkd2p. Our genetic screen has identified the fission yeast Hippo pathways SIN and MOR as crucial for the regulation of Pkd2p. Both are highly conserved kinase cascades that are essential for cell proliferation. SIN antagonizes Pkd2p activity, while MOR synergizes with Pkd2p. However, the mechanism is unclear. We will 1) Determine how MOR and SIN regulate cellular calcium during cytokinesis through calcium-imaging. 2) Determine how MOR and SIN regulate Pkd2p in cell size expansion. 3) Determine how MOR promotes the cell cycle-dependent localization of Pkd2p. 4) Determine whether Pkd2p is a direct substrate of the MOR kinase Orb6p. Aim 2. Determine how the Pkd2p channel is activated. Pkd2 channel opens in response to mechanical force in vitro, but the mechanism is unclear. We will test the proposal that Pkd2p is a channel sensitive to the force driving the yeast cell growth. We will 1) Determine how Pkd2p regulates calcium when the cells are stimulated by external force. 2) Probe how Pkd2p senses osmotic stimuli and the lipid environment in vitro through a collaboration with Allen Liu’s group (University of Michigan). 3) Determine whether Pkd2p channel allows ions other than calcium to pass through, using patch clamp, through a collaboration with Du Jianyang’s group (University of Tennessee). Aim 3 Determine how Pkd2p regulates the actin re-organization during cytokinesis. Calcium can activate two highly conserved molecules Cam1p and Ppb1p. We will determine how they contribute to the role of Pkd2p in cytokinesis. We will determine 1) how Pkd2p regulates the Cam1p-dependent endocytosis during cytokinesis. 2) how Pkd2p regulates the Cam1p-dependent intracellular transport. 3) how Pkd2p regulates the enzymatic activity of Ppb1p. Through this study, we expect to uncover a novel cell size regulation pathway mediated by Pkd2p channel. We will demonstrate how both internal signaling pathways and external environment play a vital role in activating this channel in cytokinesis. We will employ novel imaging methods combined with innovative in vitro techniques in our study. Our works shall help us better understand the cellular functions of the human polycystins.

在细胞生长过程中，多囊苷机制的机制机制机制 当两个子细胞分开时，细胞因子是细胞分裂的最后阶段，但对于 过渡到细胞生长，包括细胞尺寸的扩展。调节这种过渡的机制很差 理解。我们在研究时确定了钙和多囊通道PKD2P在此过程中的作用 模型生物裂变酵母的细胞因子。 PKD2P对于调节细胞大小至关重要 钙影响。多囊体是进化配置的离子通道。人类功能突变的丧失 多囊导致遗传疾病，常染色体多囊性肾脏疾病（ADPKD）。细胞功能 在这个高度保守的渠道家族中，人们对此并不理解。这项研究将确定PKD2P和 钙调节向细胞生长的过渡。 AIM 1。确定河马信号通路如何调节PKD2P。我们的遗传屏幕已经确定了 裂变酵母河马途径犯罪和MOR对于PKD2P的调节至关重要。两者都是高度保守的 激酶级联对于细胞增殖必不可少的。 SIN拮抗PKD2P活性，而MOR协同作用 与PKD2P。但是，该机制尚不清楚。我们将1）确定MOR和SIN如何调节细胞 细胞因子过程中的钙通过钙成像。 2）确定MOR和SIN如何调节细胞大小的PKD2P 扩张。 3）确定MOR如何促进PKD2P的细胞周期依赖性定位。 4）确定 PKD2P是否是MOR激酶ORB6P的直接底物。 AIM 2。确定PKD2P通道的方式 活性。 PKD2通道在体外响应机械力响应，但该机制尚不清楚。我们将 测试PKD2P是对驱动酵母细胞生长的力敏感的通道的建议。我们将确定 当细胞被外力刺激时，PKD2P如何调节钙。 2）探测PKD2P的感觉 通过与艾伦·刘（Allen Liu）的团体合作（大学），渗透刺激和脂质环境在体外 密歇根州）。 3）确定PKD2P通道是否允许使用钙除了钙以外的其他离子 通过与Du Jianyang的集团（田纳西大学）的合作，夹具。 AIM 3确定如何 PKD2P调节细胞分裂过程中肌动蛋白的重组。钙可以激活两个高度保守 分子CAM1P和PPB1P。我们将确定它们如何促进PKD2P在细胞因子中的作用。我们将 确定1）PKD2P如何调节细胞分裂期间CAM1P依赖性内吞作用。 2）如何PKD2P 调节CAM1P依赖性细胞内转运。 3）PKD2P如何调节PPB1P的酶活性。 通过这项研究，我们希望发现由PKD2P通道介导的新型细胞大小调节途径。我们 将展示内部信号通路和外部环境如何在激活中起着至关重要的作用 该通道中的细胞因子。我们将采用新颖的成像方法与创新的体外技术结合 在我们的研究中。我们的作品将有助于我们更好地了解人类多囊的细胞功能。