A protein methylation pathway in Chlamydomonas flagella is active during flagellar resorption.
A protein methylation pathway in Chlamydomonas flagella is active during flagellar resorption.
复制标题
DOI：
10.1091/mbc.e08-05-0470
复制
发表时间：
2008-10
影响因子：
3.3
通讯作者：
Mark J. Schneider;Megan M Ulland;R. Sloboda
中科院分区：
文献类型：
--
作者：
Mark J. Schneider;Megan M Ulland;R. Sloboda
在鞭毛内转运过程中，鞭毛顶端参与了马达蛋白的调控、货物的装卸和鞭毛蛋白的周转。为了开始鞭毛尖端的蛋白质组成的分析，我们使用差异凝胶电泳来比较长与短（即，再生）鞭毛。短鞭毛与长鞭毛相比，尖端蛋白质的浓度应相对于微管蛋白的浓度更高（微管蛋白在鞭毛的每单位长度上是恒定的）。我们已经鉴定的一种蛋白质是钴胺素非依赖性形式的甲硫氨酸合酶（MetE）。MetE的抗体标记鞭毛的点状图案，让人想起IFT颗粒染色，和免疫印迹分析表明，鞭毛中的MetE的量是低的全长鞭毛，增加再生鞭毛，最高的再吸收鞭毛。四个甲基化的蛋白质已被确定在再吸收鞭毛，使用特异性抗体的不对称二甲基精氨酸残基。这些蛋白质几乎只存在于轴丝部分中，并且这些蛋白质的甲基化形式在全长和再生鞭毛中基本上不存在。由于大多数细胞在细胞分裂前吸收纤毛/鞭毛，这些数据表明鞭毛蛋白甲基化与细胞周期进展之间存在联系。
During intraflagellar transport (IFT), the regulation of motor proteins, the loading and unloading of cargo and the turnover of flagellar proteins all occur at the flagellar tip. To begin an analysis of the protein composition of the flagellar tip, we used difference gel electrophoresis to compare long versus short (i.e., regenerating) flagella. The concentration of tip proteins should be higher relative to that of tubulin (which is constant per unit length of the flagellum) in short compared with long flagella. One protein we have identified is the cobalamin-independent form of methionine synthase (MetE). Antibodies to MetE label flagella in a punctate pattern reminiscent of IFT particle staining, and immunoblot analysis reveals that the amount of MetE in flagella is low in full-length flagella, increased in regenerating flagella, and highest in resorbing flagella. Four methylated proteins have been identified in resorbing flagella, using antibodies specific for asymmetrically dimethylated arginine residues. These proteins are found almost exclusively in the axonemal fraction, and the methylated forms of these proteins are essentially absent in full-length and regenerating flagella. Because most cells resorb cilia/flagella before cell division, these data indicate a link between flagellar protein methylation and progression through the cell cycle.