title: Identification of sequences mediating guanylyl cyclase dimerization.
abstract: Deletion mutagenesis was used to identify sequences required for dimerization and enzymatic activity of the intracellular domain of the membrane guanylyl cyclase, GC-A. The intracellular domain of GC-A contains a protein kinase-like domain near its amino terminus, a guanylyl cyclase catalytic domain near its carboxyl terminus, and, between these domains, a region of unknown function predicted to form an amphipathic alpha-helix. Gel filtration analysis of deletion mutants of the GC-A intracellular domain suggested that a 43 amino acid sequence within the interdomain region was both necessary and sufficient for dimerization and was required for guanylyl cyclase catalytic activity. The ability of this sequence to mediate protein dimerization was confirmed in the yeast two-hybrid system, in which its fusion to the lexA DNA-binding domain and to the VP16 transcriptional activation domain led to their dimerization and consequent activation of a lexA-HIS3 gene. Thus, we have identified sequences responsible for dimerization of the intracellular domain of a guanylyl cyclase and shown that they are required for enzyme activity. Modulation of their interaction may be important in guanylyl cyclase activation.
authors.affiliation: Vollum Institute, Oregon Health Sciences University, Portland 97201-3098.
authors.forename: E M
authors.initials: EM
authors.lastname: Wilson
authors.forename: M
authors.initials: M
authors.lastname: Chinkers
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001704:Biopolymers; D002850:Chromatography, Gel; D006162:Guanylate Cyclase / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009838:Oligodeoxyribonucleotides; D017384:Sequence Deletion
chemical_list: D001704:Biopolymers; D009838:Oligodeoxyribonucleotides; D006162:Guanylate Cyclase