分析蛋白質TLK-1和DLC-1在線蟲有絲分裂中的特性

Abstract

In Eukaryotes, the cell cycle is under delicate control. Different phosphorylation state of a protein often leads to different activity, thus a number of protein kinases play important roles in mitosis. The C. elegans tousled-like kinase TLK-1 is a serine/threonine kinase that is important for DNA condensation and segregation. The tlk-1(RNAi) embryos arrested at approximately 55 cells stage and showed aneuploidy. To study the expression pattern of TLK-1, we generated TLK-1 antibodies. We show that TLK-1 is localized in the interphase nucleus but diffuses to the cytosol after nuclear envelope breakdown during mitosis. We found that TLK-1 is likely to act in chromosome segregation through DLC-1. DLC-1, a subunit of cytoplasmic dynein complex, interacts with TLK-1 in a yeast 2-hybrid system. By using time-course microscopic analysis we show that the depletion of dlc-1 causes defects in spindle assembly and chromosome segregation. Using immuno-staining we found that DLC-1 is enriched in mitotic centrosomes and spindle in wild-type but not tlk-1(RNAi) embryos. We conclude TLK-1 may mediate chromosome segregation by controlling the localization of DLC-1 to the mitotic centrosomes and spindles.