Phosphorylation of RIM1alpha by PKA triggers presynaptic long-term potentiation at cerebellar parallel fiber synapses

Cell. 2003 Oct 3;115(1):49-60. doi: 10.1016/s0092-8674(03)00727-x.


Presynaptic activation of protein kinase A (PKA) induces LTP in cerebellar parallel fiber synapses. Presynaptic LTP is known to require the active zone protein RIM1alpha, but the underlying induction mechanism remains unclear. We now show that PKA directly phosphorylates RIM1alpha at two sites. Using paired recordings from cultured cerebellar granule and Purkinje neurons, we demonstrate that LTP is absent in neurons from RIM1alpha KO mice but is rescued by presynaptic expression of RIM1alpha. Mutant RIM1alpha lacking the N-terminal phosphorylation site is unable to rescue LTP in RIM1alpha knockout neurons but selectively suppresses LTP in wild-type neurons. Our findings suggest that PKA-mediated phosphorylation of the active zone protein RIM1alpha at a single N-terminal site induces presynaptic LTP.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenylyl Cyclases / metabolism
  • Amino Acid Sequence
  • Animals
  • Cells, Cultured
  • Cerebellum / cytology
  • Cerebellum / metabolism*
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Electrophysiology
  • GTP-Binding Proteins*
  • Long-Term Potentiation / physiology*
  • Mice
  • Mice, Knockout
  • Molecular Sequence Data
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurons / cytology
  • Neurons / metabolism
  • Phosphorylation
  • Presynaptic Terminals / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment
  • Serine / metabolism
  • Synapses / metabolism*
  • Transfection


  • Nerve Tissue Proteins
  • Recombinant Fusion Proteins
  • Rim protein, mammalian
  • Rims1 protein, mouse
  • Serine
  • Cyclic AMP-Dependent Protein Kinases
  • GTP-Binding Proteins
  • Adenylyl Cyclases