title: Synaptic distribution of the endocytic accessory proteins AP180 and CALM.
abstract: Clathrin-coated vesicles mediate a variety of endocytosis pathways in cells, including endocytic events at synapses. AP180 and clathrin assembly lymphoid myeloid leukemia protein (CALM) are clathrin accessory proteins that promote the formation of clathrin-coated vesicles. Both proteins bind to membrane lipids through their epsin N-terminal homology domains and interact with clathrin and related protein components through their carboxyl-terminal peptide motifs. We examine their neuronal expression and synaptic distribution. We show that both proteins are detected in synapses but demonstrate different distribution patterns. AP180 is located predominantly in presynaptic profiles, whereas CALM is found nonselectively in pre- and postsynaptic profiles and also in perisynaptic processes. These observations reveal an unexpected relationship between AP180 and the presumed non-neuronal homologue CALM. We propose that both AP180 and CALM function as endocytic accessory proteins at synapses, but each may regulate distinct clathrin pathways.
authors.affiliation: Laboratory of Neurosciences, National Institute on Aging/National Institutes of Health, Baltimore, Maryland 21224, USA. yaopa@grc.nia.nih.gov
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Yao
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Petralia
authors.forename: Ittai
authors.initials: I
authors.lastname: Bushlin
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Furukawa
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D022163:Clathrin-Coated Vesicles / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology; D006624:Hippocampus / Q000378:metabolism* / Q000648:ultrastructure; D034041:Monomeric Clathrin Assembly Proteins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D016716:PC12 Cells; D017729:Presynaptic Terminals / Q000378:metabolism*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013569:Synapses / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D034041:Monomeric Clathrin Assembly Proteins; C499980:Picalm protein, rat; C439023:clathrin assembly protein AP180