title: LIM kinase activity is required for microtubule organising centre positioning in mouse oocyte meiosis.
abstract: LIM kinase 1 (LIMK1) activity is essential for cell migration and cell cycle progression. Little is known about LIMK1 expression and function in mammalian oocytes. In the present study we assessed LIMK1 protein expression, subcellular distribution and function during mouse oocyte meiosis. Western blot analysis revealed high and stable expression of LIMK1 from the germinal vesicle (GV) to MII stage. In contrast, activated LIMK1 (i.e. LIMK1 phosphorylated at threonine 508 (pLIMK1Thr508)) was only detected after GV breakdown, with levels increasing gradually to peak at MI and MII. Immunofluorescence showed pLIMK1Thr508was colocalised with the microtubule organising centre (MTOC) components pericentrin and γ-tubulin at the spindle poles. A direct interaction between γ-tubulin and pLIMK1Thr508was confirmed by co-immunoprecipitation. LIMK inhibition with 1μM BMS3 damaged MTOC protein localisation to spindle poles, undermined the formation and positioning of functional MTOC and thus disrupted spindle formation and chromosome alignment. These effects were phenocopied by microinjection of LIMK1 antibody into mouse oocytes. In summary, the data demonstrate that LIMK activity is essential for MTOC organisation and distribution and so bipolar spindle formation and maintenance in mouse oocytes.
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110886, China.
authors.forename: Yubo
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Du
authors.affiliation: Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Sciences and Technology, China Agricultural University, Beijing, 100094, China.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Tian
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.
authors.forename: Yuanjing
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ma
mesh_terms: D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D054461:Lim Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008540:Meiosis / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D022101:Microtubule-Organizing Center / Q000187:drug effects / Q000378:metabolism*; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D008941:Spindle Apparatus / Q000187:drug effects / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D054461:Lim Kinases; C515893:Limk1 protein, mouse