title: Phosphorylation of Tara by Plk1 is essential for faithful chromosome segregation in mitosis.
abstract: Trio-associated repeat on actin (Tara) is an F-actin binding protein and regulates actin cytoskeletal organization. In our previous study, we have found that Tara associates with telomeric repeat binding factor 1 (TRF1) and mediates the function of TRF1 in mitotic regulation. We also found that overexpression HECTD3, a member of HECT E3 ubiquitin ligases, enhances the ubiquitination of Tara in vivo and promotes the degradation of Tara, and such degradation of Tara facilitates cell cycle progression. However, less is known about the post-translational modification of Tara in mitosis. Here we show that Tara is a novel Polo-like kinase 1 (Plk1) target protein. Plk1 interacts with and phosphorylates Tara in vivo and in vitro. Actually, the Thr-457 in Tara was a bona fide in vivo phosphorylation site for Plk1. Interestingly, we found that the centrosomal localization of Tara depended on the Thr-457 phosphorylation and the kinase activity of Plk1. Furthermore, overexpression of non-phosphorylatable mutant of Tara caused aberrant mitosis delay in HeLa cells. Our study demonstrated that Plk1-mediated phospho-dependent centrosomal localization of Tara is important for faithful chromosome segregation, and provided novel insights into understanding on the role of Plk1 in cooperation with Tara in mitotic progression.
authors: The First Affiliated Hospital of Zhejiang University Medical School, Hangzhou 310003, China.
authors: Yuanyuan
authors: Y
authors: Zhu
authors: Chong
authors: C
authors: Wang
authors: Jianping
authors: J
authors: Lan
authors: Jian
authors: J
authors: Yu
authors: Changjiang
authors: C
authors: Jin
authors: He
authors: H
authors: Huang
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D020090:Chromosome Segregation; D006367:HeLa Cells; D006801:Humans; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D008938:Mitosis; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D035321:Telomeric Repeat Binding Protein 1 / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D008840:Microfilament Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D035321:Telomeric Repeat Binding Protein 1; D000097869:Polo-Like Kinase 1; C425471:TRIOBP protein, human