Protein kinase injection reduces voltage-dependent potassium currents.
Intracellular iontophoretic injection of the catalytic subunit of cyclic adenosine monophosphate-dependent protein kinase increased input resistance and decreased a delayed voltage-dependent K+ current of the type B photoreceptor in the nudibranch Hermissenda crassicornis to a greater extent than an early, rapidly inactivating K+ current (IA). This injection also enhanced the long-lasting depolarization of type B cells after a light step. These findings suggest the involvement of cyclic adenosine monophosphate-dependent phosphorylation in the differential regulation of photoreceptor K+ currents particularly during illumination. On the other hand, conditioning-induced changes in IA may also be regulated by a different type of phosphorylation (for example, Ca2+-dependent).
D000818:Animals; D002118:Calcium / Q000502:physiology; D002147:Calmodulin / Q000502:physiology; D000242:Cyclic AMP / Q000502:physiology; D007473:Ion Channels / Q000502:physiology; D008974:Mollusca; D010750:Phosphoproteins / Q000502:physiology; D010786:Photoreceptor Cells / Q000502:physiology*; D011188:Potassium / Q000502:physiology*; D011494:Protein Kinases / Q000502:physiology*
D002147:Calmodulin; D007473:Ion Channels; D010750:Phosphoproteins; D000242:Cyclic AMP; D011494:Protein Kinases; D011188:Potassium; D002118:Calcium