Proteomic Analysis Detects Cytoskeletal-Related Proteins That Interact With the Intracellular C1 Domain of Adenylyl Cyclase 6
Lipid rafts are specialized structures of the plasma membrane that have an altered lipid composition as well as links to the cytoskeleton. These structures are membrane domains expressing high concentrations of signaling proteins such as receptors, G-proteins, and certain isoforms of adenylyl cyclase (AC). The mechanism by which AC6 is localized in lipid rafts or caveolae is unknown. We attempted to identify proteins interacting with the intracellular C1 domain of AC6 using proteomics. We expressed a protein corresponding to amino acids 306–692 of human AC6 in Cos-7 cells then immunoprecipitated the expressed protein via a fused epitope and analyzed the samples by MALDI/TOF mass spectrometry. Of the many proteins identified, 26 of the proteins had high association values with the AC6 C1 domain. Cytoskeleton-related proteins such as smooth muscle actin, tubulin, MAP2, MAP4, CDC42 and Rho-GEF were found to interact with the bait protein. Immunoprecipitation studies confirm these interactions. While further studies are needed to characterize the exact relationship between AC6, lipid rafts and microtubules, our study contributes to growing evidence that cytoskeletal and lipid organization are functionally interdependent elements responsible for AC6 localization.
M Thangavel, X Liu and RS Ostrom. Proteomic analysis detects cytoskeletal-related proteins that interact with the intracellular C1 domain of adenylyl cyclase 6. FASEB J, 22(1):728.1, 2008.
Federation of American Society of Experimental Biology (FASEB)