A nuclear location for Ca2+-activated adenylyl cyclases I and III in neurones

Calcium/calmodulin-sensitive adenylyl cyclases are increasingly recognised as important factors in memory formation and synaptic plasticity. We have examined the distributions: of adenylyl cyclases types I, III, and VIlI within rat primary sensory neurons. Immunofluorescence revealed distinct staining for adenylyl cyclases type I and III, but not adenylyl cyclase type VIII, within the cell nucleus. Western blots suggest that a processed form of adenylyl cyclase type III may be found within primary neurons and PC12 cells as a 70-kDa protein. We propose that the observed nuclear adenylyl cyclases are soluble forms of the cyclases. (C) 2001 Elsevier Science B.V. All rights reserved.