NCBI Summary:
Casein kinase II is a serine/threonine protein kinase that phosphorylates acidic proteins such as casein. It is involved in various cellular processes, including cell cycle control, apoptosis, and circadian rhythm. The kinase exists as a tetramer and is composed of an alpha, an alpha-prime, and two beta subunits. The alpha subunits contain the catalytic activity while the beta subunits undergo autophosphorylation. The protein encoded by this gene represents the alpha subunit. Multiple transcript variants encoding different protein isoforms have been found for this gene. [provided by RefSeq, Apr 2018]
General function
DNA repair, Enzyme, Transferase
Comment
Cellular localization
Cytoplasmic
Comment
The casein kinase 2α promotes the occurrence polycystic ovary syndrome. Yu CJ et al. (2020) Polycystic ovary syndrome (PCOS) is a complicated reproductive endocrine disease characterized by hyperandrogenism, polycystic ovaries, and anovulation. Previous studies have revealed that androgen receptors (ARs) are strongly associated with hyperandrogenism and abnormalities in folliculogenesis in patients with PCOS. However, the kinases responsible for androgen receptor activity, especially in granulosa cells, and the role of casein kinase 2α (CK2α) specifically in the pathogenesis of PCOS, remain unknown. Here, we show that both CK2α protein and mRNA levels were higher in luteinized granulosa cells of patients with PCOS compared with non-PCOS, as well as in the ovarian tissues of mice with a dehydroepiandrosterone-induced PCOS-like phenotype, compared with controls. In addition, CK2α not only interacted with AR in vivo and in vitro, but it also phosphorylated and stabilized AR, triggering AR and ovulation related genes excessive expression. CK2α also promoted cell proliferation in the KGN cell line and inhibited apoptosis. Collectively, the finding highlighted that the CK2α-AR axis probably caused the etiology of the PCOS. Thus, CK2α might be a promising clinical therapeutic target for PCOS treatment.//////////////////
Ovarian function
Oocyte maturation, Early embryo development
Comment
Casein kinase 2 modulates the spindle assembly checkpoint to orchestrate porcine oocyte meiotic progression. ShiYang X et al. (2020) CK2 (casein kinase 2) is a serine/threonine-selective protein kinase that has been involved in a variety of cellular processes such as DNA repair, cell cycle control and circadian rhythm regulation. However, its functional roles in oocyte meiosis have not been fully determined. We report that CK2 is essential for porcine oocyte meiotic maturation by regulating spindle assembly checkpoint (SAC). Immunostaining and immunoblotting analysis showed that CK2 was constantly expressed and located on the chromosomes during the entire oocyte meiotic maturation. Inhibition of CK2 activity by its selective inhibitor CX-4945 impaired the first polar body extrusion and arrested oocytes at M I stage, accompanied by the presence of BubR1 at kinetochores, indicative of activated SAC. In addition, we found that spindle/chromosome structure was disrupted in CK2-inhibited oocytes due to the weakened microtubule stability, which is a major cause resulting in the activation of SAC. Last, we found that the level DNA damage as assessed by γH2A.X staining was considerably elevated when CK2 was inhibited, suggesting that DNA damage might be another critical factor leading to the SAC activation and meiotic failure of oocytes. Our findings demonstrate that CK2 promotes the porcine oocyte maturation by ensuring normal spindle assembly and DNA damage repair.//////////////////Inhibition of casein kinase 2 blocks G2/M transition in early embryo mitosis but not in oocyte meiosis in mouse. Lin F et al. (2017) Casein kinase 2 (CK2) is a highly conserved, ubiquitously expressed serine/threonine protein kinase with hundreds of substrates. The role of CK2 in the G2/M transition of oocytes, zygotes, and 2-cell embryos was studied in mouse by enzyme activity inhibition using the specific inhibitor 4, 5, 6, 7-tetrabromobenzotriazole (TBB). Zygotes and 2-cell embryos were arrested at G2 phase by TBB treatment, and DNA damage was increased in the female pronucleus of arrested zygotes. Further developmental ability of arrested zygotes was reduced, but that of arrested 2-cell embryos was not affected after releasing from inhibition. By contrast, the G2/M transition in oocytes was not affected by TBB. These results indicate that CK2 activity is essential for mitotic G2/M transition in early embryos but not for meiotic G2/M transition in oocytes.//////////////////