Role of CK2 alpha subunit in idiopathic male infertility

Protein kinase CK2 which was formerly known as casein kinase is a ubiquitously expressed protein kinase. Its expression and its activity as a protein kinase is closely connected with proliferation i.e. rapidly proliferating cells have high amounts of the enzyme and its activity in general higher than in normal cells. Protein kinase CK2 is composed of two regulatory beta subunits and two Catalytic alpha, alpha subunits, but these subunits are also found in its free form. Although CK2 is expressed in every tissue, there are some differences in the expression level in various tissues. CK2alpha is most highly expressed in brain and testes whereas only low amounts of CK2alpha are found in other tissues. The regulatory beta subunit and the catalytic alpha subunit are both absolutely necessary for the survival of cells, because the Knockouts are lethal during embryogenesis. Mice with a CK2alpha Knockout are viable however the male mice are infertile. Materials and Methods: 83 men were involved in this study, they were 17 normal men and 66 men with idiopathic infertility problems. Required sperm samples were obtained from an in vitro fertilization unit. The sperms were extracted and their protein content is determined. Equal amounts of protein will be loaded on SDS-polyacrylamide gel. After a Western Blotting, the CK2alpha, CK2alpha and CK2beta subunits were detected by specific antibodies. Results: the presence percentage of CK2alpha was 12.1% in infertile men group, and it was significantly lower compared to control group, which was 100 %. Conclusion: the absence of CK2alpha from the sperm would be used as a marker for the identification of idiopathic men infertility

Phospholipase D is activated and phosphorylated by casein kinase-II in human U87 astroglioma cells

Elevated expression of protein casein kinase II (CKII) stimulated basal phospholipase D (PLD) activity as well as PMA-induced PLD activation in human U87 astroglioma cells. Moreover, CKII-selective inhibitor, emodin and apigenin suppressed PMA-induced PLD activation in a dose-dependent manner as well as basal PLD activity, suggesting the involvement of CKII in the activation of both PLD1 and PLD2. CKII was associated with PLD1 and PLD2 in co-transfection experiments. Furthermore, CKII induced serine/threonine phosphorylation of PLD2 in vivo, and the multiple regions of PLD2 were phosphorylated by CKII in vitro kinase assay using glutathione S-transferase-PLD2 fusion protein fragments. Elevated expression of CKII or PLD increased cell proliferation but pretreatment of cells with 1-butanol suppressed CKII-induced cell proliferation. These results suggest that CKII is involved in proliferation of U87 cells at least in part, through stimulation of PLD activity.