Regulation of ROP signaling in cell division and cell expansion by a small ROPGAP family

ROPGAP 小家族对细胞分裂和细胞扩张中 ROP 信号传导的调节

• 批准号: 277031791
• 负责人: Dr. Sabine Müller
• 金额: --
• 依托单位: Department Biologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/277031791?language=en
• 关键词: Regulation; ROP; signaling; cell; division

The establishment of cell polarity, an unequal distribution of cellular content, is a prerequisite of cellular morphogenesis. Cell polarity is under genetic control and coordinated at the cell-, tissue- and organ- level, to ensure the stereotypic reproduction of functional plant organs. The evolutionary conserved family of Rho of plant (ROP) small cytosolic GTPases serves as molecular switches in cell polarity signaling and orchestrate the spatio-temporal distribution of cellular content. Regulatory proteins enable the switching between activity and inactivity of the small Rho-GTPases. The Guanine nucleotide exchange factors (RopGEF), replace guanosin diphosphate (GDP) for guanosine triphosphate (GTP) to promote ROP activation. On the contrary, GTPase activating proteins (RopGAP) accelerate the intrinsically slow hydrolysis of GTP and render the respective target ROPs inactive. Little is known about the regulation of ROP-inactivation. Our previous work on ROP inactivation by the PHGAP subfamily of RopGAPs, implicated them in cell division. They localize to the plasma membrane and the division site and require the motor-protein kinesin-12 POK for retention at that site. We hypothesis that PHGAPs act in the inactivation of specific ROPs to set up the division site/actin depleted zone to ensure normal cell division. We will gain further insights into the regulation and cellular dynamic of PHGAPs during cell division. We will clarify which ROPs are inactivated by PHGAPs and we will identify novel interaction partners to investigate how PHGAP protein function is regulated. In addition we will establish transient reconstitution assays to recreate ROP-signaling modules and investigate their spatio-temporal regulation.

细胞极性的建立是细胞含量的不相等的分布，是细胞形态发生的先决条件。细胞极性处于遗传控制之下，并在细胞，组织和器官水平进行协调，以确保刻板印象的植物器官的刻板印象。植物Rho（ROP）小胞质GTPase的进化保守家族用作细胞极性信号传导中的分子开关，并策划了细胞含量的时空分布。调节蛋白可以在小rho-GTPase的活性和不活动之间进行切换。鸟嘌呤核苷酸交换因子（ROPGEF），代替三磷酸鸟嘌呤（GTP）的鸟嘌呤二磷酸（GDP）以促进ROP激活。相反，GTPase激活蛋白（ROPGAP）加速了GTP的本质缓慢水解，并使各个靶标ROPS无活性。关于ROP灭活的调节知之甚少。我们以前关于ropgap的phgap亚家族灭活ROP的工作，牵涉到细胞分裂。它们位于质膜和分裂部位，并要求运动蛋白驱动蛋白12 POK在该地点保留。我们假设Phgap在特定ROP的失活中起作用，以建立分裂位点/肌动蛋白耗尽的区域以确保正常的细胞分裂。我们将进一步了解细胞分裂过程中phgap的调节和细胞动态。我们将阐明哪些ROP被Phgap灭活，我们将确定新型的相互作用伙伴，以研究如何调节PhGAP蛋白功能。此外，我们将建立瞬态重建测定法，以重新创建ROP信号模块并研究其时空调节。