ADP regulates SNF1, the Saccharomyces cerevisiae homolog of AMP-activated protein kinase.
The SNF1 protein kinase complex plays an essential role in regulating gene expression in response to the level of extracellular glucose in budding yeast. SNF1 shares structural and functional similarities with mammalian AMP-activated protein kinase. Both kinases are activated by phosphorylation on a threonine residue within the activation loop segment of the catalytic subunit. Here we show that ADP is the long-sought metabolite that activates SNF1 in response to glucose limitation by protecting the enzyme against dephosphorylation by Glc7, its physiologically relevant protein phosphatase. We also show that the regulatory subunit of SNF1 has two ADP binding sites. The tighter site binds AMP, ADP, and ATP competitively with NADH, whereas the weaker site does not bind NADH, but is responsible for mediating the protective effect of ADP on dephosphorylation. Mutagenesis experiments suggest that the general mechanism by which ADP protects against dephosphorylation is strongly conserved between SNF1 and AMPK.
MRC Clinical Sciences Centre, Cellular Stress Group, Hammersmith Hospital Campus, Imperial College, DuCane Road, London, UK.
Faith V
FV
Mayer
Richard
R
Heath
Elizabeth
E
Underwood
Matthew J
MJ
Sanders
David
D
Carmena
Rhonda R
RR
McCartney
Fiona C
FC
Leiper
Bing
B
Xiao
Chun
C
Jing
Philip A
PA
Walker
Lesley F
LF
Haire
Roksana
R
Ogrodowicz
Stephen R
SR
Martin
Martin C
MC
Schmidt
Steven J
SJ
Gamblin
David
D
Carling
D000244:Adenosine Diphosphate / Q000737:chemistry / Q000378:metabolism*; D000263:Adenylate Kinase / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D020134:Catalytic Domain / Q000235:genetics; D017124:Conserved Sequence; D004789:Enzyme Activation / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology; D005947:Glucose / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D054730:Protein Interaction Domains and Motifs; D054645:Protein Phosphatase 1 / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013379:Substrate Specificity; D013912:Threonine / Q000378:metabolism
D029701:Saccharomyces cerevisiae Proteins; D013912:Threonine; D000244:Adenosine Diphosphate; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases; D000263:Adenylate Kinase; C092048:GLC7 protein, S cerevisiae; D054645:Protein Phosphatase 1; D005947:Glucose