Mu2 adaptin facilitates but is not essential for synaptic vesicle recycling in Caenorhabditis elegans.
Synaptic vesicles must be recycled to sustain neurotransmission, in large part via clathrin-mediated endocytosis. Clathrin is recruited to endocytic sites on the plasma membrane by the AP2 adaptor complex. The medium subunit (micro2) of AP2 binds to cargo proteins and phosphatidylinositol-4 ,5-bisphosphate on the cell surface. Here, we characterize the apm-2 gene (also called dpy-23), which encodes the only micro2 subunit in the nematode Caenorhabditis elegans. APM-2 is highly expressed in the nervous system and is localized to synapses; yet specific loss of APM-2 in neurons does not affect locomotion. In apm-2 mutants, clathrin is mislocalized at synapses, and synaptic vesicle numbers and evoked responses are reduced to 60 and 65%, respectively. Collectively, these data suggest AP2 micro2 facilitates but is not essential for synaptic vesicle recycling.
Gu
Mingyu
M
Howard Hughes Medical Institute and Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
Schuske
Kim
K
Watanabe
Shigeki
S
Liu
Qiang
Q
Baum
Paul
P
Garriga
Gian
G
Jorgensen
Erik M
EM
D033962:Adaptor Protein Complex 2 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002966:Clathrin / Q000378:metabolism*; D004705:Endocytosis; D009154:Mutation; D009469:Neuromuscular Junction / Q000378:metabolism* / Q000648:ultrastructure; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D009435:Synaptic Transmission; D013572:Synaptic Vesicles / Q000378:metabolism*
D033962:Adaptor Protein Complex 2; D029742:Caenorhabditis elegans Proteins; D002966:Clathrin; C527887:Dpy-23 protein, C elegans; D011993:Recombinant Fusion Proteins