An Sfi1p-Like Centrin-Binding Protein Mediates Centrin-Based Ca2+-Dependent Contractility in Paramecium tetraurelia
An Sfi1p-Like Centrin-Binding Protein Mediates Centrin-Based Ca2+-Dependent Contractility in Paramecium tetraurelia
复制标题
Sfi1p 样中心蛋白结合蛋白介导四尿草履虫中基于中心蛋白的 Ca2 依赖性收缩力
作者：
Delphine Gogendeau;J. Beisson;N. G. de Loubresse;J. L. Le Caer;F. Ruiz;Jean Cohen;L. Sperling;F. Koll;C. Klotz
摘要Sfi 1 p是一种对纺锤体极体复制至关重要的酿酒酵母中心蛋白结合蛋白，其先前的特征和结构分析已经提出了解释中心蛋白介导的Ca 2+依赖性收缩过程的分子模型（S. Li，长穗条锈菌A. M. Sandercock，P. V.罗宾逊，R. L.威廉姆斯和J. V. Kilmartin，细胞生物学杂志173：867-877，2006）。这样的过程可以分析使用草履虫tetraurelia，其中含有一个大的钙依赖性收缩细胞骨架网络，纤毛下晶格（ICL）。先前的生物化学和遗传学研究表明，ICL由不同的中心蛋白亚型和高分子量中心蛋白相关蛋白组成，其在de <$maille <$（dem 1）突变体中的尺寸减小与ICL的组织缺陷相关。使用来自高分子量蛋白的序列来探测草履虫基因组序列，我们表征了PtCenBP 1基因，其编码460 kDa的蛋白。PtCenBP 1 p显示ca的六个几乎完美的重复。ScSfi 1 p基因编码427个氨基酸（aa），具有89个潜在的中心蛋白结合位点，其共有基序为LLX 11 F/LX 2 WK/R，与ScSfi 1 p的中心蛋白结合位点相似。较小的（260-kDa）蛋白质编码的dem 1突变PtCenBP 1等位基因仅包括两个重复的427个氨基酸和46个中心蛋白结合位点。通过使用RNA干扰和绿色荧光蛋白融合实验，我们表明PtCenBP 1 p形成ICL的骨架，并在其组装和收缩性中起着至关重要的作用。这项研究提供了第一个在体内演示的作用，Sfi 1 p样蛋白质的中心蛋白介导的钙依赖性收缩过程。
ABSTRACT The previous characterization and structural analyses of Sfi1p, a Saccharomyces cerevisiae centrin-binding protein essential for spindle pole body duplication, have suggested molecular models to account for centrin-mediated, Ca2+-dependent contractility processes (S. Li, A. M. Sandercock, P. Conduit, C. V. Robinson, R. L. Williams, and J. V. Kilmartin, J. Cell Biol. 173:867-877, 2006). Such processes can be analyzed by using Paramecium tetraurelia, which harbors a large Ca2+-dependent contractile cytoskeletal network, the infraciliary lattice (ICL). Previous biochemical and genetic studies have shown that the ICL is composed of diverse centrin isoforms and a high-molecular-mass centrin-associated protein, whose reduced size in the démaillé (dem1) mutant correlates with defective organization of the ICL. Using sequences derived from the high-molecular-mass protein to probe the Paramecium genome sequence, we characterized the PtCenBP1 gene, which encodes a 460-kDa protein. PtCenBP1p displays six almost perfect repeats of ca. 427 amino acids (aa) and harbors 89 potential centrin-binding sites with the consensus motif LLX11F/LX2WK/R, similar to the centrin-binding sites of ScSfi1p. The smaller (260-kDa) protein encoded by the dem1 mutant PtCenBP1 allele comprises only two repeats of 427 aa and 46 centrin-binding sites. By using RNA interference and green fluorescent protein fusion experiments, we showed that PtCenBP1p forms the backbone of the ICL and plays an essential role in its assembly and contractility. This study provides the first in vivo demonstration of the role of Sfi1p-like proteins in centrin-mediated Ca2+-dependent contractile processes.
影响因子：
3.3
作者：
Guerra, C;Wada, Y;Satir, P
通讯作者：
Satir, P
影响因子：
7
作者：
Crooks, GE;Hon, G;Brenner, SE
通讯作者：
Brenner, SE