%0 Journal Article %A Masaki Saito %A Linran Cui %A Marina Hirano %A Guanjie Li %A Teruyuki Yanagisawa %A Takeya Sato %A Jun Sukegawa %T Activity of adenylyl cyclase type 6 is suppressed by direct binding of the cytoskeletal protein 4.1G %D 2019 %R 10.1124/mol.119.116426 %J Molecular Pharmacology %P mol.119.116426 %X The G protein-coupled receptor (GPCR) signaling pathways mediated by trimeric G proteins have been extensively elucidated, but their associated regulatory mechanisms remain unclear. Parathyroid hormone (PTH)/PTH-related protein receptor (PTHR) is a GPCR coupled with Gs and Gq. Gs activates adenylyl cyclases (ACs), which produces 3', 5'-cyclic adenosine monophosphate (cAMP) to regulate various cell fates. We previously showed that cell surface expression of PTHR was increased by its direct interaction with a subcortical cytoskeletal protein, 4.1G, whereas PTHR-mediated Gs/AC/cAMP signaling was suppressed by 4.1G through an unknown mechanism in HEK293 cells. In the present study, we found that AC type 6 (AC6), one of the major ACs activated downstream of PTHR, interacts with 4.1G in HEK293 cells, and the N-terminus of AC6 (AC6-N) directly and selectively binds to the FERM domain of 4.1G (4.1G-FERM) in vitro. AC6-N was distributed at the plasma membrane, which was disturbed by knockdown of 4.1G. An AC6-N mutant, AC6-N-3A, wherein three consecutive arginine residues were mutated to alanine residues, altered both binding to 4.1G-FERM and its plasma membrane distribution in vivo. Further, we overexpressed AC6-N to competitively inhibit the interaction of endogenous AC6 and 4.1G in cells. cAMP production induced by forskolin, an adenylyl cyclase activator, and PTH-(1-34) was enhanced by AC6-N expression and 4.1G-knockdown. In contrast, AC6-N-3A had no impact on forskolin- and PTH-(1-34)-induced cAMP productions, respectively. These data provide a novel regulatory mechanism that AC6 activity is suppressed by the direct binding of 4.1G to AC6-N, resulting in attenuation of PTHR-mediated Gs/AC6/cAMP signaling.SIGNIFICANCE STATEMENT This study investigated the mechanism by which PTHR controls adenylyl cyclase 6 activity through their direct interaction with the cytoskeletal protein, 4.1G. We believe that our study makes a significant contribution to the literature due to the diverse and central roles of adenylyl cyclases in driving cellular processes and the identification of a novel mechanism by which adenylyl cyclase 6 activity is effectively tuned without altering its location at the plasma membrane. %U https://molpharm.aspetjournals.org/content/molpharm/early/2019/08/05/mol.119.116426.full.pdf