Cloning and Characterization of the Cyclic Guanosine Monophosphate-Inhibited Phosphodiesterase PDE3A Expressed in Mouse Oocyte

摘要: In the preovulatory follicle, oocyte meiotic resumption occurs soon after LH surge and is associated with a decrease in cAMP. Inhibition of cAMP degradation blocks germinal vesicle breakdown as well activation promoting factor, both hallmarks reentry into cell cycle. situ pharmacological analysis rodent ovaries suggested presence phosphodiesterase 3 (PDE3) germ but not somatic compartment. Here we have investigated structure properties PDE form expressed mouse oocytes. Polymerase chain reactions using cDNA library template, primers based on conserved sequence rat human PDE3As, yielded partial fragments corresponding to PDE3A. Further screening subsequent ligation individual clones PDE3A containing entire coding region To determine kinetic this PDE, cDNAs encoding full-length NH2-truncation forms Delta 1 (D346aa) 2 (D608aa) were Leydig tumor cells. Whereas recombinant protein was always found particulate fraction, truncated PDE3As recovered mostly soluble fraction. The Michaelis constant values for hydrolysis similar those intact fulllength or (0.2‐0.5 mM). More importantly, there good correlation between rank potency selective nonselective compounds inhibiting activity derived from cumulus-oocyte complexes blocking meiosis. These data provide evidence that enzyme involved control cyclic adenosine monophosphate, meiosis, development, ovulatory cycle, phosphodiesterases