Department of Plant Biology, University of Minnesota, St. Paul, MN 55108, USA.
Mol Biol Cell. 2013 Mar;24(5):588-600. doi: 10.1091/mbc.E12-10-0718. Epub 2013 Jan 2.
The length of Chlamydomonas flagella is tightly regulated. Mutations in four genes-LF1, LF2, LF3, and LF4-cause cells to assemble flagella up to three times wild-type length. LF2 and LF4 encode protein kinases. Here we describe a new gene, LF5, in which null mutations cause cells to assemble flagella of excess length. The LF5 gene encodes a protein kinase very similar in sequence to the protein kinase CDKL5. In humans, mutations in this kinase cause a severe form of juvenile epilepsy. The LF5 protein localizes to a unique location: the proximal 1 μm of the flagella. The proximal localization of the LF5 protein is lost when genes that make up the proteins in the cytoplasmic length regulatory complex (LRC)-LF1, LF2, and LF3-are mutated. In these mutants LF5p becomes localized either at the distal tip of the flagella or along the flagellar length, indicating that length regulation involves, at least in part, control of LF5p localization by the LRC.
衣藻鞭毛的长度受到严格调控。四个基因（LF1、LF2、LF3 和 LF4）的突变会导致细胞组装出三倍于野生型长度的鞭毛。LF2 和 LF4 编码蛋白激酶。在这里，我们描述了一个新基因 LF5，其缺失突变会导致细胞组装出过长的鞭毛。LF5 基因编码的蛋白激酶在序列上与蛋白激酶 CDKL5 非常相似。在人类中，该激酶的突变会导致一种严重的青少年癫痫。LF5 蛋白定位于一个独特的位置：鞭毛的近端 1μm。当构成细胞质长度调节复合物（LRC）的基因（LF1、LF2 和 LF3）发生突变时，LF5 蛋白的近端定位会丢失。在这些突变体中，LF5p 要么位于鞭毛的远端尖端，要么沿着鞭毛长度定位，表明长度调节至少部分涉及由 LRC 控制 LF5p 的定位。
