Adenylyl cyclase type II domains involved in Gbetagamma stimulation.
Mammalian particulate adenylyl cyclases contain two transmembrane regions (M(1) and M(2)) and two cytosolic domains (C(1) and C(2)) forming the catalytic core. The cytosolic domains are subdivided into a highly conserved region (part a) and a region with lower similarity (part b). Hypothetical models exist that account for the mechanism by which Galpha(s) and forskolin stimulate mammalian adenylyl cyclase. In contrast, little is known about how Gbetagamma dimers regulate catalysis. The so-called QEHA region located in the C(2a) domain of type II adenylyl cyclase has been proposed to represent a site of interaction. Here we show (i) that the QEHA region directly interacts with Gbetagamma but (ii) that it is of minor importance for the stimulation of type II adenylyl cyclase because it can be replaced by corresponding, nonidentical regions of other adenylyl cyclase isoforms without altering the stimulatory effect of Gbetagamma and (iii) that the C(1b) region is necessary for Gbetagamma to exert a stimulatory effect on adenylyl cyclase type II as in a C(1b) deletion mutant the Gbetagamma regulation was specifically impeded whereas the Galpha(s)- and forskolin-mediated stimulation was maintained.
Weitmann
S
S
Institut für Pharmakologie, Freie Universität Berlin, Thielallee 67-73, 14195 Berlin, Germany.
Schultz
G
G
Kleuss
C
C
D000262:Adenylyl Cyclases / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002384:Catalysis; D002417:Cattle; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D017124:Conserved Sequence; D003600:Cytosol / Q000201:enzymology; D018076:DNA, Complementary; D019281:Dimerization; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D020962:Heterotrimeric GTP-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D018411:Spodoptera; D014162:Transfection
D018076:DNA, Complementary; C118981:G-protein Beta gamma; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D010446:Peptide Fragments; D011994:Recombinant Proteins; D020962:Heterotrimeric GTP-Binding Proteins; D000262:Adenylyl Cyclases; C100622:adenylyl cyclase 2