Identification and characterization of a nerve terminal-enriched amphiphysin isoform.
Amphiphysin is a nerve terminal-enriched protein thought to function in synaptic vesicle endocytosis, in part through Src homology 3 (SH3) domain-mediated interactions with dynamin and synaptojanin. Here, we report the characterization of a novel amphiphysin isoform (termed amphiphysin II) that was identified through a homology search of the data base of expressed sequence tags. Antibodies specific to amphiphysin II recognize a 90-kDa protein on Western blot that is brain-specific and highly enriched in nerve terminals. Like amphiphysin (now referred to as amphiphysin I), amphiphysin II binds to dynamin and synaptojanin through its SH3 domain. Further, both proteins bind directly to clathrin in an SH3 domain-independent manner. Taken together, these data suggest that amphiphysin II may participate with amphiphysin I in the regulation of synaptic vesicle endocytosis.
Ramjaun
A R
AR
Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Québec H3A 2B4, Canada.
Micheva
K D
KD
Bouchelet
I
I
McPherson
P S
PS
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001923:Brain Chemistry; D002966:Clathrin / Q000378:metabolism; D034281:Dynamins; D004705:Endocytosis; D020558:GTP Phosphohydrolases / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D051381:Rats; D013572:Synaptic Vesicles / Q000378:metabolism; D018909:src Homology Domains
D002966:Clathrin; D009419:Nerve Tissue Proteins; C075637:amphiphysin; C097702:synaptojanin; D010744:Phosphoric Monoester Hydrolases; D020558:GTP Phosphohydrolases; D034281:Dynamins