cAMP-GEFII is a direct target of cAMP in regulated exocytosis
N Ozaki, T Shibasaki, Y Kashima, T Miki… - Nature cell …, 2000 - nature.com
N Ozaki, T Shibasaki, Y Kashima, T Miki, K Takahashi, H Ueno, Y Sunaga, H Yano…
Nature cell biology, 2000•nature.comAlthough 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, Ca 2+-dependent secretion that is not blocked by an inhibitor of cAMP …
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, Ca 2+-dependent secretion that is not blocked by an inhibitor of cAMP …
Abstract
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, Ca 2+-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.
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