PT  - JOURNAL ARTICLE
AU  - Rachael L. Neve
AU  - Robert Coopersmith
AU  - Donna L. McPhie
AU  - Christopher Santeufemio
AU  - Kara G. Pratt
AU  - Curran J. Murphy
AU  - Stephanie D. Lynn
TI  - The Neuronal Growth-Associated Protein GAP-43 Interacts with Rabaptin-5 and Participates in Endocytosis
AID  - 10.1523/JNEUROSCI.18-19-07757.1998
DP  - 1998 Oct 01
TA  - The Journal of Neuroscience
PG  - 7757--7767
VI  - 18
IP  - 19
4099  - http://www.jneurosci.org/content/18/19/7757.short
4100  - http://www.jneurosci.org/content/18/19/7757.full
SO  - J. Neurosci.1998 Oct 01; 18
AB  - Structural plasticity of nerve cells is a requirement for activity-dependent changes in the brain. The growth-associated protein GAP-43 is thought to be one determinant of such plasticity, although the molecular mechanism by which it mediates dynamic structural alterations at the synapse is not known. GAP-43 is bound by calmodulin when Ca2+ levels are low, and releases the calmodulin when Ca2+ levels rise, suggesting that calmodulin may act as a negative regulator of GAP-43 during periods of low activity in the neurons. To identify the function of GAP-43 during activity-dependent increases in Ca2+ levels, when it is not bound to calmodulin, we sought proteins with which GAP-43 interacts in the presence of Ca2+. We show here that rabaptin-5, an effector of the small GTPase Rab5 that mediates membrane fusion in endocytosis, is one such protein. We demonstrate that GAP-43 regulates endocytosis and synaptic vesicle recycling. Modulation of endocytosis by GAP-43, in association with rabaptin-5, may constitute a common molecular mechanism by which GAP-43 regulates membrane dynamics during its known roles in activity-dependent neurotransmitter release and neurite outgrowth.