Adenylyl cyclase types II-VI were detected in endothelial cells from a wide variety of peripheral tissues. In the current study, the very sensitive technique of RT-PCR demonstrated expression of multiple adenylyl cyclase isoforms in uterine smooth muscle cells, consistent with the demonstration here of a generally widespread expression of adenylyl cyclase isoforms with the exception of type I. This suggests that the regulation of cellular levels of cAMP in many cells is the result of the integrated regulation of multiple isoforms of adenylyl cyclase by inputs (e.g., Ca2+/calmodulin, (З7 subunits, PKC) from multiple other signaling pathways. buy ortho tri-cyclen
In the current study we detected the expression of a splice variant of adenylyl cyclase type IV in both fresh and cultured rat uterine muscle cells. A splice variant for this isoform has not been previously reported, although splice variants for adenylyl cyclase type V and functionally different splice variants for type VIII have been described. In the current study we did not attempt to evaluate the potential functional significance of the type IV splice variant that encodes an additional eight amino acids in the 5′ end of the C2a region of the protein (Fig. 4b). A large portion of the C2a region is highly conserved among all adenylyl cyclases, and even greater homology of this region is seen among the adenylyl cyclase subfamily that includes types II, IV, and VII. The splice variant of type IV identified in the present study occurs in the 5′ end of the C2a region, which is not highly homologous among all ad-enylyl cyclases but which is highly conserved within the type II, IV, and VII subfamily. The eight-amino acid addition in this newly identified splice variant of type IV results in even greater homology of this new splice variant with types II and VII than does the previously published type IV sequence (Fig. 4b).