Inhibition of protein kinase D disrupts spindle formation and actin assembly during porcine oocyte maturation
Abstract
The protein kinase D (PKD) subfamily, comprising PKD1, PKD2, and PKD3, is a distinct group of serine/threonine kinases. PKD has been extensively linked to various physiological processes, including immune responses, apoptosis, and cell proliferation. However, its role in oocyte development remains unclear. In this study, we explored the regulatory functions of PKD during porcine oocyte maturation. Our findings demonstrated that PKD is expressed in porcine oocytes, and its inhibition resulted in the failure of meiosis resumption and first polar body extrusion. Further analysis revealed that PKD inhibition disrupted spindle assembly and chromosome alignment, likely through its influence on MAPK phosphorylation. Additionally, PKD was found to phosphorylate cofilin, facilitating actin assembly and influencing cortical actin distribution, highlighting its role in cytoskeletal CID755673 dynamics. Moreover, a reduction in PKD expression was observed in postovulatory aging porcine oocytes, potentially linking PKD to cytoskeletal defects in aged oocytes. Collectively, these findings suggest that PKD plays a crucial role in porcine oocyte maturation by regulating spindle organization and actin assembly.