title: Drosophila Amphiphysin is implicated in protein localization and membrane morphogenesis but not in synaptic vesicle endocytosis.
abstract: Amphiphysin family members are implicated in synaptic vesicle endocytosis, actin localization and one isoform is an autoantigen in neurological autoimmune disorder; however, there has been no genetic analysis of Amphiphysin function in higher eukaryotes. We show that Drosophila Amphiphysin is localized to actin-rich membrane domains in many cell types, including apical epithelial membranes, the intricately folded apical rhabdomere membranes of photoreceptor neurons and the postsynaptic density of glutamatergic neuromuscular junctions. Flies that lack all Amphiphysin function are viable, lack any observable endocytic defects, but have abnormal localization of the postsynaptic proteins Discs large, Lethal giant larvae and Scribble, altered synaptic physiology, and behavioral defects. Misexpression of Amphiphysin outside its normal membrane domain in photoreceptor neurons results in striking morphological defects. The strong misexpression phenotype coupled with the mild mutant and lack of phenotypes suggests that Amphiphysin acts redundantly with other proteins to organize specialized membrane domains within a diverse array of cell types.
authors.affiliation: Institute of Neuroscience, HHMI, University of Oregon 1254, Eugene, OR 97403, USA.
authors.forename: A C
authors.initials: AC
authors.lastname: Zelhof
authors.forename: H
authors.initials: H
authors.lastname: Bao
authors.forename: R W
authors.initials: RW
authors.lastname: Hardy
authors.forename: A
authors.initials: A
authors.lastname: Razzaq
authors.forename: B
authors.initials: B
authors.lastname: Zhang
authors.forename: C Q
authors.initials: CQ
authors.lastname: Doe
mesh_terms: D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002451:Cell Compartmentation; D016764:Cell Polarity; D003598:Cytoskeletal Proteins; D004330:Drosophila; D029721:Drosophila Proteins; D004705:Endocytosis; D005136:Eye Proteins / Q000235:genetics / Q000302:isolation & purification; D007814:Larva; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000302:isolation & purification*; D009469:Neuromuscular Junction / Q000737:chemistry* / Q000196:embryology / Q000473:pathology; D017956:Photoreceptor Cells, Invertebrate / Q000648:ultrastructure; D020033:Protein Isoforms / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013569:Synapses / Q000737:chemistry* / Q000473:pathology; D013570:Synaptic Membranes / Q000737:chemistry* / Q000473:pathology; D013572:Synaptic Vesicles
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; D005136:Eye Proteins; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; C107943:bif protein, Drosophila; C075637:amphiphysin