CDC14B Acts Through FZR1 (CDH1) to Prevent Meiotic Maturation of Mouse Oocytes1

Abstract

Meiotic maturation in oocytes is a prolonged process that is unique because of cell cycle arrests at prophase of meiosis I (MI) and at metaphase of meiosis II (MII). Fluctuations in cyclin-dependent kinase 1 (CDK1/CDC2A) activity govern meiotic progression, yet little is known about how these fluctuations are achieved. CDC14 is a highly conserved dual-specificity phosphatase that counteracts the function of proteins phosphorylated by CDK. Mammals contain two CDC14 homologs, CDC14A and CDC14B. We report that CDC14B localizes with the meiotic spindle in mouse oocytes, and (unlike somatic cells) it does not localize in the nucleolus. Oocytes that overexpress CDC14B are significantly delayed in resuming meiosis and fail to progress to MII, whereas oocytes depleted of CDC14B spontaneously resume meiosis under conditions that normally inhibit meiotic resumption. Depletion of FZR1 (CDH1), a regulatory subunit of the anaphase-promoting complex/cyclosome that targets cyclin B1 (CCNB1) for ubiquitin-mediated proteolysis, partially restores normal timing of meiotic resumption in oocytes with excess CDC14B. These studies also reveal that experimentally altering CDC14B levels generates eggs with abnormal spindles and with chromosome alignment perturbations. Our data indicate that CDC14B is a negative regulator of meiotic resumption and may regulate MI in mouse oocytes.

The APC/C in female mammalian meiosis I

“…Cell division cycle homologue 14 (Cdc14) is a dual-specificity phosphatase that counteracts Cdk-mediated phosphorylation with two homologues, Cdc14A and Cdc14B, being expressed in mammals. Recently, Cdc14B depletion using double-stranded RNA-mediated RNA interference was found to promote GVBD during culture in milrinone and was associated with elevated histone H1 kinase activity (Schindler & Schultz 2009b). Conversely, over-expression of Cdc14B from exogenous cRNA inhibited GVBD along with which H1 kinase activity and cyclin B1 levels were reduced (Schindler & Schultz 2009b).…”

“…Recently, Cdc14B depletion using double-stranded RNA-mediated RNA interference was found to promote GVBD during culture in milrinone and was associated with elevated histone H1 kinase activity (Schindler & Schultz 2009b). Conversely, over-expression of Cdc14B from exogenous cRNA inhibited GVBD along with which H1 kinase activity and cyclin B1 levels were reduced (Schindler & Schultz 2009b). Notably, the effects of Cdc14B over-expression could be attenuated by depleting Cdh1, altogether indicating that Cdc14B probably positively regulates APC/C Cdh1 , thereby contributing to the G2/prophase arrest state.…”

Mouse Oocyte Microinjection, Maturation and Ploidy Assessment

“…Other routine analyses we use in the laboratory include monitoring the kinetics by which the oocytes progress through meiosis, immunofluorescence to analyze spindle formation and chromosome alignment and egg activation or in vitro fertilization to assess the developmental consequences of the oocyte manipulation 14,15,16,17 .…”

Functional redundancy between Cdc14 phosphatases in zebrafish ciliogenesis

“…Previous studies have uncovered multiple and, in many cases, divergent functions for each of these enzymes. Indeed, CDC14A was found to play a role in mitotic timing (Vazquez-Novelle et al, 2010;Sacristan et al, 2011), cytokinesis (Bembenek and Yu, 2001;Kaiser et al, 2002Kaiser et al, , 2004Mailand et al, 2002;Krasinska et al, 2007), meiosis (Schindler and Schultz, 2009b), DNA repair , and transcriptional repression (Clemente-Blanco et al, 2011), whereas CDC14B was implicated in G1-phase length regulation (Rodier et al, 2008), centriole duplication (Wu et al, 2008), mitosis (Tumurbaatar et al, 2011), spindle stability (Cho et al, 2005), meiosis (Schindler and Schultz, 2009a), DNA damage response (Bassermann et al, 2008; or repair Wei et al, 2011), activation of the zygotic genome (Buffone et al, 2009), ciliogenesis (Cl ement et al, 2011), and oncogenic transformation (Chiesa et al, 2011).…”

“…In contrast, endogenous and tagged CDC14B proteins are detected in the nucleolus during interphase Mailand et al, 2002;Berdougo et al, 2008;Cl ement et al, 2011) as well as the centrosomes (Wu et al, 2008) and microtubules (Cho et al, 2005). During mitosis and meiosis, Cdc14B localizes at the spindle (Buffone et al, 2009;Schindler and Schultz, 2009a,b;Cl ement et al, 2011), the spindle poles (Schindler and Schultz, 2009a), and the chromosomes (Berdougo et al, 2008). The reported functional differences and distinct sub-cellular localizations between CDC14A and CDC14B might suggest that these phosphatases evolved towards independent roles.…”