Signalling complexes associated with adenylyl cyclase II are assembled during their biosynthesis

Cell Signal. 2007 Mar;19(3):481-9. doi: 10.1016/j.cellsig.2006.07.021. Epub 2006 Sep 18.


We have previously demonstrated that adenylyl cyclase II (ACII) interacts with beta2-adrenergic receptors and heterotrimeric G proteins as part of a pre-assembled signalling complex. In this study, we further show that AC interacts with these proteins before it is targetted to the cell surface. Using a combination of approaches including bioluminescence resonance energy transfer (BRET) in concert with subcellular fractionation, we show that ACII and beta2AR initially interact in the ER. Further, dominant-negative Rab1 and Sar1 GTPases which block anterograde trafficking out of the ER have no effect on either ACII/receptor or ACII/Gbetagamma protein interactions. However, DN Rab1 and Sar1 constructs (but not DN Rabs 2, 6, 8 or 11) prevent the inclusion of Galpha subunits in ACII signalling complexes suggesting it assembles into the complex at a slightly later stage. Thus, like Kir3.1 inwardly rectifying potassium channels, signalosomes containing ACII are formed during their biosynthesis and not in response to agonist at the cell surface.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylyl Cyclases / metabolism*
  • Binding Sites
  • Cell Line
  • Endoplasmic Reticulum / metabolism
  • Energy Transfer
  • GTP-Binding Protein alpha Subunits, Gi-Go / biosynthesis*
  • GTP-Binding Protein beta Subunits / biosynthesis*
  • Green Fluorescent Proteins / metabolism
  • Heterotrimeric GTP-Binding Proteins / biosynthesis*
  • Humans
  • Luciferases / metabolism
  • Luminescence
  • Microscopy, Fluorescence
  • Protein Binding
  • Receptors, Adrenergic, beta-2 / metabolism
  • Signal Transduction*
  • Subcellular Fractions


  • GTP-Binding Protein beta Subunits
  • Receptors, Adrenergic, beta-2
  • Green Fluorescent Proteins
  • Luciferases
  • GTP-Binding Protein alpha Subunits, Gi-Go
  • Heterotrimeric GTP-Binding Proteins
  • Adenylyl Cyclases