cAMP-GEFII is a direct target of cAMP in regulated exocytosis

Nat Cell Biol. 2000 Nov;2(11):805-11. doi: 10.1038/35041046.


Although cAMP is well known to regulate exocytosis in many secretory cells, its direct target in the exocytotic machinery is not known. Here we show that cAMP-GEFII, a cAMP sensor, binds to Rim (Rab3-interacting molecule, Rab3 being a small G protein) and to a new isoform, Rim2, both of which are putative regulators of fusion of vesicles to the plasma membrane. We also show that cAMP-GEFII, through its interaction with Rim2, mediates cAMP-induced, Ca2+-dependent secretion that is not blocked by an inhibitor of cAMP-dependent protein kinase (PKA). Accordingly, cAMP-GEFII is a direct target of cAMP in regulated exocytosis and is responsible for cAMP-dependent, PKA-independent exocytosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • COS Cells
  • Carrier Proteins
  • Chlorocebus aethiops
  • Cyclic AMP / metabolism*
  • Cyclic AMP Receptor Protein / genetics
  • Cyclic AMP Receptor Protein / metabolism*
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • DNA, Complementary
  • Exocytosis / physiology*
  • GTP-Binding Proteins*
  • Mice
  • Molecular Sequence Data
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Rats


  • Carrier Proteins
  • Cyclic AMP Receptor Protein
  • DNA, Complementary
  • Nerve Tissue Proteins
  • Rim protein, mammalian
  • Rims1 protein, mouse
  • Rims1 protein, rat
  • Rims2 protein, mouse
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • GTP-Binding Proteins

Associated data

  • GENBANK/AB021131
  • GENBANK/AB021132