The Arabidopsis thaliana K(+)-uptake permease 7 (AtKUP7) contains a functional cytosolic adenylate cyclase catalytic centre

FEBS Lett. 2015 Dec 21;589(24 Pt B):3848-52. doi: 10.1016/j.febslet.2015.11.038. Epub 2015 Nov 27.

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.

Keywords: Adenylate cyclase; Arabidopsis thaliana; Cyclic adenosine 3′,5′-monophosphate; Second messenger.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylyl Cyclases / metabolism*
  • Amino Acid Sequence
  • Arabidopsis Proteins / chemistry*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Arabidopsis* / cytology
  • Catalytic Domain*
  • Cytosol / enzymology*
  • Escherichia coli / genetics
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation
  • Potassium Channels / chemistry*
  • Potassium Channels / genetics
  • Potassium Channels / metabolism*

Substances

  • Arabidopsis Proteins
  • KUP7 protein, Arabidopsis
  • Potassium Channels
  • Adenylyl Cyclases