title: A clathrin coat assembly role for the muniscin protein central linker revealed by TALEN-mediated gene editing.
abstract: Clathrin-mediated endocytosis is an evolutionarily ancient membrane transport system regulating cellular receptivity and responsiveness. Plasmalemma clathrin-coated structures range from unitary domed assemblies to expansive planar constructions with internal or flanking invaginated buds. Precisely how these morphologically-distinct coats are formed, and whether all are functionally equivalent for selective cargo internalization is still disputed. We have disrupted the genes encoding a set of early arriving clathrin-coat constituents, FCHO1 and FCHO2, in HeLa cells. Endocytic coats do not disappear in this genetic background; rather clustered planar lattices predominate and endocytosis slows, but does not cease. The central linker of FCHO proteins acts as an allosteric regulator of the prime endocytic adaptor, AP-2. By loading AP-2 onto the plasma membrane, FCHO proteins provide a parallel pathway for AP-2 activation and clathrin-coat fabrication. Further, the steady-state morphology of clathrin-coated structures appears to be a manifestation of the availability of the muniscin linker during lattice polymerization.
authors.affiliation: Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States.
authors.forename: Perunthottathu K
authors.initials: PK
authors.lastname: Umasankar
authors.affiliation: Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States.
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States.
authors.forename: James R
authors.initials: JR
authors.lastname: Thieman
authors.affiliation: Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States.
authors.forename: Anupma
authors.initials: A
authors.lastname: Jha
authors.affiliation: Department of Medicine, Washington University School of Medicine, St. Louis, United States.
authors.forename: Balraj
authors.initials: B
authors.lastname: Doray
authors.affiliation: Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States.
authors.forename: Simon C
authors.initials: SC
authors.lastname: Watkins
authors.affiliation: Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States.
authors.forename: Linton M
authors.initials: LM
authors.lastname: Traub
mesh_terms: D033962:Adaptor Protein Complex 2 / Q000378:metabolism; D000494:Allosteric Regulation; D000818:Animals; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D002966:Clathrin / Q000378:metabolism* / Q000648:ultrastructure; D017124:Conserved Sequence; D004705:Endocytosis; D004720:Endonucleases / Q000378:metabolism*; D050556:Fatty Acid-Binding Proteins; D056426:Genetic Loci; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D017393:RNA Editing; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*
chemical_list: D033962:Adaptor Protein Complex 2; D002966:Clathrin; C524557:FCHO1 protein, human; C497031:FCHO2 protein, human; D050556:Fatty Acid-Binding Proteins; D008565:Membrane Proteins; D010455:Peptides; D019269:Phosphatidylinositol 4,5-Diphosphate; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D004720:Endonucleases
keywords: E. coli; TALEN; adaptor; biochemistry; cell biology; clathrin; endocytosis; human