Different activity regulation and subcellular localization of LIMK1 and LIMK2 during cell cycle transition |
| |
Authors: | Sumi Tomoyuki Hashigasako Atsuko Matsumoto Kunio Nakamura Toshikazu |
| |
Affiliation: | Molecular Regenerative Medicine, Department of Biochemistry and Molecular Biology, Osaka University Graduate School of Medicine, 2-2-B7 Yamadaoka, Suita, Osaka 565-0871, Japan. |
| |
Abstract: | LIM kinases (LIMK1 and LIMK2) regulate actin cytoskeletal reorganization through phosphorylating and inactivating cofilin, an actin-depolymerizing factor of actin filaments. Here, we describe a detailed analysis of the cell-cycle-dependent activity of LIMK2, and a subcellular localization of LIMK1 and LIMK2. The activity of LIMK2, distinct from LIMK1, toward cofilin phosphorylation did not change in the normal cell division cycle. In contrast, LIMK2 was hyperphosphorylated and its activity was markedly increased when HeLa cells were synchronized at mitosis with nocodazole treatment. Immunofluorescence analysis showed that LIMK1 was localized at cell-cell adhesion sites in interphase and prophase, redistributed to the spindle poles during prometaphase to anaphase, and accumulated at the cleavage furrow in telophase. In contrast, LIMK2 was diffusely localized in the cytoplasm during interphase, redistributed to the mitotic spindle, and finally to the spindle midzone during anaphase to telophase. These findings suggest that LIMK2 is activated in response to microtubule disruption, and that LIMK1 and LIMK2 may play different roles in regulating for the mitotic spindle organization, chromosome segregation, and cytokinesis during the cell division cycle. |
| |
Keywords: | LIMK Actin Cofilin Mitosis Mitotic spindle Microtubule Cytokinesis Phosphorylation |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|