α-SNAP inhibits AMPK signaling to reduce mitochondrial biogenesis and dephosphorylates Thr172 in AMPKα in vitro

Nat Commun. 2013:4:1559. doi: 10.1038/ncomms2565.

Abstract

The AMP-activated protein kinase (AMPK) regulates metabolism in normal and pathological conditions and responds to nutrients, hormones, anti-diabetic drugs and physical exercise. AMPK is activated by the kinase LKB1 and inactivated by phosphatases whose identities remain uncertain. Here we show that AMPK associates with α-SNAP, an adapter that enables disassembly of cis-SNARE complexes formed during membrane fusion. Knockdown of α-SNAP activates AMPK to phosphorylate its endogenous substrates acetyl CoA carboxylase and Raptor, and provokes mitochondrial biogenesis. AMPK phosphorylation is rescued from α-SNAP RNA interference by LKB1 knockdown or expression of wild-type but not mutated α-SNAP. Recombinant wild-type but not mutated α-SNAP dephosphorylates pThr172 in AMPKα in vitro. Overexpression of wild-type but not mutated α-SNAP prevents AMPK activation in cells treated with agents to elevate AMP concentration. The mouse α-SNAP mutant hyh (hydrocephalus with hop gait) shows enhanced binding and inhibition of AMPK. By negatively controlling AMPK, α-SNAP therefore potentially coordinates membrane trafficking and metabolism.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • AMP-Activated Protein Kinases / metabolism*
  • Adenosine Triphosphate / pharmacology
  • Animals
  • Enzyme Activation / drug effects
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Humans
  • Madin Darby Canine Kidney Cells
  • Mice
  • Mitochondrial Turnover* / drug effects
  • Mutant Proteins / metabolism
  • Oxygen Consumption / drug effects
  • Phosphorylation / drug effects
  • Protein Binding / drug effects
  • RNA, Small Interfering / metabolism
  • Signal Transduction* / drug effects
  • Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins / metabolism*
  • Threonine / metabolism*

Substances

  • Mutant Proteins
  • RNA, Small Interfering
  • Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins
  • Threonine
  • Adenosine Triphosphate
  • AMP-Activated Protein Kinases