Inhibition of protein kinase D disrupts spindle formation and actin assembly during porcine oocyte maturation

Abstract

Protein kinase D (PKD) subfamily which includes PKD1, PKD2 and PKD3 is a novel family of serine/threonine kinases. PKD has been widely implicated in the regulation of multiple physiological effects including immune responses, apoptosis and cell proliferation. However, the roles of PKD in oocytes have not been fully clarified. In this study we investigated the regulatory functions of PKD during porcine oocyte maturation. Our results indicated that PKD expressed in porcine oocytes and the inhibition of PKD family activity led to the failure of meiosis resumption and the first polar body extrusion. Further analysis indicated that the spindle assembly and chromosome alignment were disrupted after PKD family inhibition, and this might be through its regulatory role on MAPK phosphorylation. We also found that PKD phosphorylated cofilin for actin assembly, which further affected cortical actin distribution, indicating the roles of PKD family on cytoskeleton. In addition, a decreased expression of PKD in postovulatory aging porcine oocytes was observed, which might connect PKD with cytoskeleton defects in aged oocytes. Taken together, these results suggest that PKD possesses important functions in porcine oocyte maturation by regulating spindle organization and actin assembly.

Post-Translational Modifications in Oocyte Maturation and Embryo Development

“…However, although this PTM is important and ubiquitous, how phosphorylation regulates oocyte maturation and embryo development in mammals is still not well understood. It is speculated that phosphorylation may regulate these processes by regulating proteins involved in chromosome condensation and spindle assembly ( Swain et al, 2007 ; Zhang Y. et al, 2018 ). Using okadaic acid to inhibit protein phosphatases, chromosome condensation occurred prematurely and pig oocytes entered the GVBD stage early as a result ( Sun et al, 2002 ).…”

“…In a recent study, Akimov et al (2018) identified over 63,000 unique ubiquitination sites on 9,200 proteins in human cell lines by mass spectrometry. It is relevant to the regulation of the cell cycle, fertilization, oocyte maturation, and embryo development ( Xuan et al, 2018 ; Zhang Y. et al, 2018 ).…”

“…Moreover, CRL4 is also a common E3 enzyme. DCAF13, which is one of its substrate adaptors, is expressed from the 4-cell stage to blastocyst stage during mouse embryo development ( Zhang Y. et al, 2018 ). CRL4 forms a complex with DCAF13 and regulates the degradation of SUV39H1 through polyubiquitination, thus playing a role in embryo development ( Zhang Y. et al, 2018 ).…”

The mystery of monozygotic twinning II: What can monozygotic twinning tell us about Amyoplasia from a review of the various mechanisms and types of monozygotic twinning?

“…Trauma, temperature, irradiation, starvation, chemical imbalance, and physical separation of blastocoel cells can all produce MZ twins (Aston et al, 2008). Double‐yolked eggs and two‐headed reptiles and amphibians are seen “in the wild,” and even conjoined domestic animals have been reported, but essentially all normally occurring twins (or other multiples) in animals are the result of polyovulation (e.g., more than one ova is ovulated and then successfully fertilized): cow (Hashiyada, 2017; Jiang et al, 2019; Klein et al, 2006; Shojaei Saadi et al, 2017; Song et al, 2012; Taylor & Murray, 1991), dog (Hogenboom, 2016; Joonè et al, 2016, 2017; Moura et al, 2017; Urhausen et al, 2017), fish (Samarin et al, 2015), frog (Tokmakov & Sato, 2019), horse (Govaere et al, 2009), lemur (St Clair et al, 2014), monkey (Schramm & Paprocki, 2004), mouse (Freund et al, 2013; Kitami & Nadeau, 2002; McLaren et al, 1995), pig (Corner, 1922; Kim et al, 2019; Park et al, 2019; Zhang et al, 2018), polar bear (Malenfant et al, 2016), rabbit (Bomsel‐Helmreich & Papiernik‐Berkhauer, 1976; Orgebin‐Crist, 1968; Shaver & Carr, 1967), salmon (Ytteborg et al, 2010), sheep (Celi et al, 2007), and starfish (Limatola et al, 2019). Some of the recent works in animals are related to “overripe ova” and how to improve the outcome of old eggs (Jiang et al, 2019; Kim et al, 2019; Song et al, 2012; Tokmakov & Sato, 2019).…”

“…The nucleolus and its role in ribosome production could be key (Gupta & Santoro, 2020). In animals, certain treatment of the “overripe ova” and dying cells seems to increase the viability of the embryo (Jiang et al, 2019; Kim et al, 2019; Lin et al, 2018; Park et al, 2019; Zhang et al, 2018, 2019). Is there a cellular survival response in an aging ovum (Green, 2020)?…”