title: AGAP1, a novel binding partner of nitric oxide-sensitive guanylyl cyclase.
abstract: Nitric oxide (NO)-sensitive soluble guanylyl cyclase (sGC) is the major cytosolic receptor for NO, catalyzing the conversion of GTP to cGMP. In a search for proteins specifically interacting with human sGC, we have identified the multidomain protein AGAP1, the prototype of an ArfGAP protein with a GTPase-like domain, Ankyrin repeats, and a pleckstrin homology domain. AGAP1 binds through its carboxyl terminal portion to both the alpha1 and beta1 subunits of sGC. We demonstrate that AGAP1 mRNA and protein are co-expressed with sGC in human, murine, and rat cells and tissues and that the two proteins interact in vitro and in vivo. We also show that AGAP1 is prone to tyrosine phosphorylation by Src-like kinases and that tyrosine phosphorylation potently increases the interaction between AGAP1 and sGC, indicating that complex formation is modulated by reversible phosphorylation. Our findings may hint to a potential role of AGAP1 in integrating signals from Arf, NO/cGMP, and tyrosine kinase signaling pathways.
authors.affiliation: Institute for Biochemistry II, University of Frankfurt Medical School, Theodor-Stern-Kai 7, Building 75, D-60590 Frankfurt, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Meurer
authors.forename: Sylke
authors.initials: S
authors.lastname: Pioch
authors.forename: Kristina
authors.initials: K
authors.lastname: Wagner
authors.forename: Werner
authors.initials: W
authors.lastname: Müller-Esterl
authors.forename: Steffen
authors.initials: S
authors.lastname: Gross
mesh_terms: D020727:ADP-Ribosylation Factors / Q000737:chemistry / Q000502:physiology*; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D019556:COS Cells; D002460:Cell Line; D003432:Cross-Linking Reagents / Q000494:pharmacology; D006152:Cyclic GMP / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D019281:Dimerization; D020690:GTPase-Activating Proteins / Q000737:chemistry / Q000502:physiology*; D005822:Genetic Vectors; D006160:Guanosine Triphosphate / Q000737:chemistry; D006162:Guanylate Cyclase; D006801:Humans; D047468:Immunoprecipitation; D051379:Mice; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry*; D015398:Signal Transduction; D000071756:Soluble Guanylyl Cyclase; D013347:Subcellular Fractions / Q000378:metabolism; D014018:Tissue Distribution; D014162:Transfection; D020798:Two-Hybrid System Techniques; D014443:Tyrosine / Q000737:chemistry; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: C470574:AGAP1 protein, human; D003432:Cross-Linking Reagents; D018076:DNA, Complementary; D020690:GTPase-Activating Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D014443:Tyrosine; D006160:Guanosine Triphosphate; D019061:src-Family Kinases; D020727:ADP-Ribosylation Factors; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D006152:Cyclic GMP