LIMK1 takes part in the regulation of Aurora-A-localization on spindle during mouse oocyte meiosis / 基础医学与临床

ABSTRACT

Objective To investigate the sub-cellular distribution correlation between activated LIMK1 (pLIMK1Thr508) and Aurora-A in mouse oocyte meiosis,and changes in Aurora-A location and spindle structure in condition of LIMK1 inhibition.Methods Immunofluorescence staining was employed to detect the sub-cellular localization of pLIMK1Thr508and its spatial-temporal correlation with spindle organizing regulator Aurora-A in mouse oocyte meiosis; BMS-3, the specific inhibitor to LIMK1 activity, was applied to analyze the effects of LIMK1 inhibition on Aurora-A distribution and spindle formation. Results At meiotic prophase,pLIMK1Thr508was weakly detected and concentrated in the germinal vesicle(GV) in oocytes,with no signal of Aurora-A across the cytoplasm and nuclear area;as meiotic assumption approaching,pLIMK1Thr508left nuclear,aggregating as a single dense dote in the vicinity of nuclear, and being co-localized with the emerging Aurora-A; After germinal vesicle broke down (GVBD), pLIMK1Thr508and Aurora-A remained overlapped and concentrated as multi foci around the condensed chromosomes;at metaphase Ⅰ(MⅠ) and metaphase Ⅱ(MⅡ), pLIMK1Thr508was co-localized with Aurora-A on spindle poles;During anaphase Ⅰ(AⅠ) to telophase Ⅰ(Tel Ⅰ) progression, pLIMK1Thr508was detached from spindle poles and mainly concentrated on the cleavage furrow,while Aurora-A loosely congressed on spindle. In ad-dition, LIMK1 inhibition with BMS- 3 destroyed Aurora-A polar location and spindle formation. Conclusions pLIMK1Thr508is a microtubule organizing center (MTOC)-associated protein, may participate in spindle assembly and maintenance through regulating Aurora-A in mouse oocytes during meiotic progression.