PAK1 regulates spindle microtubule organization during oocyte meiotic maturation.
P21-activated kinase 1 (PAK1), an effector of Rho GTPase Rac 1 and Cdc42, is required for mitotic progression. However, its functions in meiosis are unclear. In the present study, we examined the expression, localization and function of PAK1 during mouse oocyte meiotic maturation and found that PAK1 was mainly associated with the meiotic spindle microtubules. Taxol treatment resulted in localization of PAK1 on spindle and aster microtubules, while nocodazole treatment induced the dispersion of PAK1 protein into the cytoplasm. Loss-of-function of PAK1 by both inhibitor treatment and morpholino oligonucleotide injection caused disorganized spindles, decreased polar body extrusion and misaligned chromosomes. In addition, inhibition of PAK1 resulted in abnormal localization of mitogen-activated protein kinase kinase (MEK). Taken together, our results suggest that PAK1 plays an important role in spindle assembly and chromosome alignment during mouse oocyte meiotic maturation.
Lin
Sheng-Li
SL
State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Qi
Shu-Tao
ST
Sun
Shao-Chen
SC
Wang
Ya-Peng
YP
Schatten
Heide
H
Sun
Qing-Yuan
QY
D000818:Animals; D008540:Meiosis / Q000502:physiology*; D051379:Mice; D008870:Microtubules / Q000187:drug effects / Q000502:physiology*; D009865:Oocytes / Q000166:cytology*; D017239:Paclitaxel / Q000494:pharmacology; D008941:Spindle Apparatus; D054462:p21-Activated Kinases / Q000502:physiology*
C515905:Pak1 protein, mouse; D054462:p21-Activated Kinases; D017239:Paclitaxel