Developmental changes of cyclic adenosine monophosphate-dependent protein kinase activity during spermatogenesis in the mouse

Cyclic AMP-dependent protein kinase. activity W8I ItUdied in germ ceIIs at different lUpI of meiosis md spenniogenesis. A constant dec:reue in total protein kinase activity W8I detected in the IOluble fraction of genn ceUs, durin. spennatogalic devdopment. TIUs dec:reue wu not IIIOciated with a redistribution of phosphorylative activity to other compartmentl of the ceDo DEAE-c:eIlulose chromatography of the c:ytosoI of pacbytene spennatocytel md round spermatidl demonstrated the praence of two isoenzyma of protein kinue e1utin. at 35 mM KCI (Peak I) md 170 mM KCI (Peak Il). A selective dec:reue in the amount of Peak I cou1d be observed with the progrcss of spennatid development, md Peak Il W8I the major form praent in e10nptinJ spermaddl. Peak Il isoenzyme W8I me most abundant form of protein kinue aIso in the IOluble fraction of epididymal spermatOZOL A simiIar deve!opmental pattem W8I obtained when cyclic AMP binding activity, rather then phosphorylative activity, wu measured alter ion exchmge chromatography of different germ celllOluble fractiona. The two protein kinue isoenzyma of germ ceUs had characteristic:l similar to those dClcribed in other ceUs of the testis md other tisaua. In particular, Peak I kinase W8I diIIoc:iated md ac:tivated by hip wt concentration md buie proteina, while Peak Il kinue W8I inaensitive to these treatmenti. These distinctive propertia of the two isoenzyma were used to measure me relative concentration of the twO forms direcdy in the crude c:ytosoI preparationa of germ ceUs. Pacbytene spermatocyte kinue activity wu dissociated by hiJh wt to a leve! comparable to that of round spermatidl. The soIuble kinue present in elonpting spermatidl wu, inatead, inaensitive to wt treatment, confmnin. the hypothesis that most of the activity praent in thia celi type hu the cbaracteristic of Peak Il.