title: Phosphorylation of CLIP-170 by Plk1 and CK2 promotes timely formation of kinetochore-microtubule attachments.
abstract: CLIP-170 is implicated in the formation of kinetochore-microtubule attachments through direct interaction with the dynein/dynactin complex. However, whether this important function of CLIP-170 is regulated by phosphorylation is unknown. Herein, we have identified polo-like kinase 1 (Plk1) and casein kinase 2 (CK2) as two kinases of CLIP-170 and mapped S195 and S1318 as their respective phosphorylation sites. We showed that a CK2 unphosphorylatable mutant lost its ability to bind to dynactin and to localize to kinetochores during prometaphase, indicating that the CK2 phosphorylation of CLIP-170 is involved in its dynactin-mediated kinetochore localization. Furthermore, we provide evidence that Plk1 phosphorylation of CLIP-170 at S195 enhances its association with CK2. Finally, we detected defects in the formation of kinetochore fibres in cells expressing the CLIP-S195A and -S1318A, but not the CLIP-S195E and -S1318D, confirming that Plk1- and CK2-associated phosphorylations of CLIP-170 are involved in the timely formation of kinetochore-microtubule attachments in mitosis.
authors.affiliation: Department of Biochemistry and Center for Cancer Research, Purdue University, West Lafayette, IN, USA.
authors.forename: Hongchang
authors.initials: H
authors.lastname: Li
authors.forename: X Shawn
authors.initials: XS
authors.lastname: Liu
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Yang
authors.forename: Yingmin
authors.initials: Y
authors.lastname: Wang
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.forename: Jerrold R
authors.initials: JR
authors.lastname: Turner
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Liu
mesh_terms: D047390:Casein Kinase II / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D000072159:Dynactin Complex; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis; D009363:Neoplasm Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D000097869:Polo-Like Kinase 1
chemical_list: D047390:Casein Kinase II; D018797:Cell Cycle Proteins; D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D012694:Serine; D000097869:Polo-Like Kinase 1; C076744:cytoplasmic linker protein 170