Schermer Bernhard, Ghenoiu Cristina, Bartram Malte, Müller Roman Ulrich, Kotsis Fruzsina, Höhne Martin, Kühn Wolfgang, Rapka Manuela, Nitschke Roland, Zentgraf Hanswalter, Fliegauf Manfred, Omran Heymut, Walz Gerd, Benzing Thomas
Renal Division and 2Children's Hospital, University Hospital Freiburg, 79106 Freiburg, Germany.
J Cell Biol. 2006 Nov 20;175(4):547-54. doi: 10.1083/jcb.200605092. Epub 2006 Nov 13.
Cilia are specialized organelles that play an important role in several biological processes, including mechanosensation, photoperception, and osmosignaling. Mutations in proteins localized to cilia have been implicated in a growing number of human diseases. In this study, we demonstrate that the von Hippel-Lindau (VHL) protein (pVHL) is a ciliary protein that controls ciliogenesis in kidney cells. Knockdown of pVHL impeded the formation of cilia in mouse inner medullary collecting duct 3 kidney cells, whereas the expression of pVHL in VHL-negative renal cancer cells rescued the ciliogenesis defect. Using green fluorescent protein-tagged end-binding protein 1 to label microtubule plus ends, we found that pVHL does not affect the microtubule growth rate but is needed to orient the growth of microtubules toward the cell periphery, a prerequisite for the formation of cilia. Furthermore, pVHL interacts with the Par3-Par6-atypical PKC complex, suggesting a mechanism for linking polarity pathways to microtubule capture and ciliogenesis.
纤毛是一种特化的细胞器,在包括机械感觉、光感知和渗透信号传导在内的多种生物学过程中发挥重要作用。定位于纤毛的蛋白质发生突变与越来越多的人类疾病有关。在本研究中,我们证明了冯·希佩尔-林道(VHL)蛋白(pVHL)是一种控制肾细胞纤毛发生的纤毛蛋白。敲低pVHL会阻碍小鼠肾内髓集合管3细胞中纤毛的形成,而在VHL阴性肾癌细胞中表达pVHL可挽救纤毛发生缺陷。使用绿色荧光蛋白标记的末端结合蛋白1标记微管正端,我们发现pVHL不影响微管生长速率,但对于将微管生长导向细胞周边是必需的,这是纤毛形成的一个先决条件。此外,pVHL与Par3-Par6-非典型蛋白激酶C复合物相互作用,提示了一种将极性途径与微管捕获和纤毛发生联系起来的机制。