title: The Arabidopsis thaliana K(+)-uptake permease 7 (AtKUP7) contains a functional cytosolic adenylate cyclase catalytic centre.
abstract: Adenylate cyclases (ACs) catalyse the formation of the second messenger cyclic adenosine 3',5'-monophosphate (cAMP) from adenosine 5'-triphosphate (ATP). Although cAMP is increasingly recognised as an important signalling molecule in higher plants, ACs have remained somewhat elusive. Here we used a search motif derived from experimentally tested guanylyl cyclases (GCs), substituted the residues essential for substrate specificity and identified the Arabidopsis thaliana K(+)-uptake permease 7 (AtKUP7) as one of several candidate ACs. Firstly, we show that a recombinant N-terminal, cytosolic domain of AtKUP7(1-100) is able to complement the AC-deficient mutant cyaA in Escherichia coli and thus restoring the fermentation of lactose, and secondly, we demonstrate with both enzyme immunoassays and mass spectrometry that a recombinant AtKUP7(1-100) generates cAMP in vitro.
authors.affiliation: Biological and Environmental Sciences & Engineering Division, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Inas
authors.initials: I
authors.lastname: Al-Younis
authors.affiliation: Biological and Environmental Sciences & Engineering Division, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Aloysius
authors.initials: A
authors.lastname: Wong
authors.affiliation: Biological and Environmental Sciences & Engineering Division, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Chris
authors.initials: C
authors.lastname: Gehring
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D003600:Cytosol / Q000201:enzymology*; D004926:Escherichia coli / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D015221:Potassium Channels / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C000607348:KUP7 protein, Arabidopsis; D015221:Potassium Channels; D000262:Adenylyl Cyclases
keywords: Adenylate cyclase; Arabidopsis thaliana; Cyclic adenosine 3′,5′-monophosphate; Second messenger