title: MsGC-II, a receptor guanylyl cyclase isolated from the CNS of Manduca sexta that is inhibited by calcium.
abstract: We describe the cloning of a receptor guanylyl cyclase, MsGC-II, from the CNS of the insect Manduca sexta. Sequence comparisons with other receptor guanylyl cyclases show that MsGC-II is most similar to a predicted guanylyl cyclase in the Drosophila genome and to vertebrate retinal guanylyl cyclases. When expressed in COS-7 cells, MsGC-II exhibited a low level of basal activity that was nearly abolished in the presence of 10 micro m calcium. Incubation with either a mammalian guanylyl cyclase-activating protein or Drosophila frequenin resulted in only mild stimulation of activity, whereas incubation of COS-7 cells expressing MsGC-II with a variety of Manduca tissue extracts failed to stimulate enzyme activity above basal levels. Analysis of the tissue distribution of MsGC-II revealed that it is nervous system specific. In the adult, MsGC-II is present in neurons in the optic lobes, antennal lobes and cellular cortex, but it is most highly expressed in subsets of intrinsic mushroom body neurons. Thus, MsGC-II appears to be a neural-specific receptor guanylyl cyclase whose activity may be regulated either directly or indirectly by calcium.
authors.affiliation: Department of Biological Structure and Function, Oregon Health and Science University, Portland 97201, USA. mortonda@ohsu.edu
authors.forename: David B
authors.initials: DB
authors.lastname: Morton
authors.forename: Alan
authors.initials: A
authors.lastname: Nighorn
mesh_terms: D000818:Animals; D019556:COS Cells; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D002490:Central Nervous System / Q000737:chemistry / Q000201:enzymology*; D003001:Cloning, Molecular; D004330:Drosophila; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000302:isolation & purification; D018402:Manduca / Q000201:enzymology*; D008969:Molecular Sequence Data; D024521:Mushroom Bodies / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D009928:Organ Specificity; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D014162:Transfection
chemical_list: D011956:Receptors, Cell Surface; D006162:Guanylate Cyclase; D002118:Calcium