Regulation of AMP-activated protein kinase by a pseudosubstrate sequence on the γ subunit

John W. Scott, Fiona A. Ross, J. K.David Liu, D. Grahame Hardie

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44 Citations (Scopus)

Abstract

The AMP-activated protein kinase (AMPK) system monitors cellular energy status by sensing AMP and ATP, and is a key regulator of energy balance at the cellular and whole-body levels. AMPK exists as heterotrimeric αβγ complexes, and the γ subunits contain two tandem domains that bind the regulatory nucleotides. There is a sequence in the first of these domains that is conserved in γ subunit homologues in all eukaryotes, and which resembles the sequence around sites phosphorylated on target proteins of AMPK, except that it has a non-phosphorylatable residue in place of serine. We propose that in the absence of AMP this pseudosubstrate sequence binds to the active site groove on the α subunit, preventing phosphorylation by the upstream kinase, LKB1, and access to downstream targets. Binding of AMP causes a conformational change that prevents this interaction and relieves the inhibition. We present several lines of evidence supporting this hypothesis.

Original languageEnglish
Pages (from-to)806-815
Number of pages10
JournalThe EMBO Journal
Volume26
Issue number3
DOIs
Publication statusPublished - 7 Feb 2007
Externally publishedYes

Keywords

  • AMP
  • AMP-activated protein kinase
  • Energy balance
  • LKB1
  • Pseudosubstrate

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