title: Inhibition of the Binding between RGS2 and β-Tubulin Interferes with Spindle Formation and Chromosome Segregation during Mouse Oocyte Maturation In Vitro.
abstract: RGS2 is a negative regulator of G protein signaling that contains a GTPase-activating domain and a β-tubulin binding region. This study aimed to determine the localization and function of RGS2 during mouse oocyte maturation in vitro. Immunofluorescent staining revealed that RGS2 was widely expressed in the cytoplasm with a greater abundance on both meiotic spindles and first/second polar bodies from the fully-grown germinal vesicle (GV) stage to the MII stages. Co-expression of RGS2 and β-tubulin could also be detected in the spindle and polar body of mouse oocytes at the MI, AI, and MII stages. Inhibition of the binding site between RGS2 and β-tubulin was accomplished by injecting anti-RGS2 antibody into GV-stage oocytes, which could result in oocytes arrest at the MI or AI stage during in vitro maturation, but it did not affect germinal vesicle breakdown. Moreover, injecting anti-RGS2 antibody into oocytes resulted in a significant reduction in the rate of first polar body extrusion and abnormal spindle formation. Additionally, levels of phosphorylated MEK1/2 were significantly reduced in anti-RGS2 antibody injected oocytes compared with control oocytes. These findings suggest that RGS2 might play a critical role in mouse oocyte meiotic maturation by affecting β-tubulin polymerization and chromosome segregation.
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guangzhou 510317, China.
authors.forename: Man-Xi
authors.initials: MX
authors.lastname: Jiang
authors.affiliation: NPFPC Key Lab of Contraceptives and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai 200032, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.affiliation: NPFPC Key Lab of Contraceptives and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai 200032, China.
authors.forename: Zhao-Gui
authors.initials: ZG
authors.lastname: Sun
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guangzhou 510317, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guangzhou 510317, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D000818:Animals; D020090:Chromosome Segregation; D005260:Female; D048369:MAP Kinase Kinase 1 / Q000378:metabolism; D048370:MAP Kinase Kinase 2 / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D009866:Oogenesis; D011485:Protein Binding; D020710:RGS Proteins / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism*; D014404:Tubulin / Q000378:metabolism*
chemical_list: D020710:RGS Proteins; C105345:Rgs2 protein, mouse; D014404:Tubulin; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482129:Map2k2 protein, mouse