Protein kinase CK2 activities in human prostatic and seminal-vesicle secretions and seminal plasma

Human prostatic secretion and seminal plasma contain certain protein kinase activities. Protein kinases play important roles in regulating a vast vari ety of cellular functions. The objective of this study was to determine whe ther one of these protein kinase activities in human prostatic secretion an d seminal plasma is due to CK2, a messenger-independent, serine/threonine p rotein kinase that has considerable potential as a regulatory enzyme. By em ploying an anti-CK2 antibody and a CK2-specific peptide substrate, we have established that CK2 is present in these secretions. Approximately 70% of t he CK2 activity present in seminal plasma of normozoospermic men (n = 49) i s correlated to the number of sperm originally present in the semen. Furthe r, both the prostate gland and the seminal vesicles are sources of CK2 acti vity in the seminal plasma of vasectomized men (n = 38). Although there was considerable variation between individuals in CK2 activity, the variation in repeat semen samples of the same vasectomized men (n = 6) was within 21% . There was no correlation of CK2 activity in seminal plasma with age for v asectomized (27-48 years, n = 38), oligozoospermic (28-43 years, n = 24), o r normozoospermic men (26-48 years, n = 49). These data suggest that the ma jority of CK2 activity in the seminal plasma of normozoospermic men origina tes from sperm but that the prostate and seminal vesicles are accessory sex -gland sources of this enzyme.