A clathrin coat assembly role for the muniscin protein central linker revealed by TALEN-mediated gene editing

Elife. 2014 Oct 10;3:e04137. doi: 10.7554/eLife.04137.

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.

Keywords: E. coli; TALEN; adaptor; biochemistry; cell biology; clathrin; endocytosis; human.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adaptor Protein Complex 2 / metabolism
  • Allosteric Regulation
  • Animals
  • Base Sequence
  • Cell Membrane / metabolism
  • Clathrin / metabolism*
  • Clathrin / ultrastructure
  • Conserved Sequence
  • Endocytosis
  • Endonucleases / metabolism*
  • Genetic Loci
  • HeLa Cells
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Molecular Sequence Data
  • Peptides / metabolism
  • Phosphatidylinositol 4,5-Diphosphate / metabolism
  • Phylogeny
  • Protein Structure, Tertiary
  • RNA Editing*
  • Rats
  • Recombinant Fusion Proteins / metabolism
  • Trans-Activators / metabolism*

Substances

  • Adaptor Protein Complex 2
  • Clathrin
  • FCHO1 protein, human
  • FCHO2 protein, human
  • Membrane Proteins
  • Peptides
  • Phosphatidylinositol 4,5-Diphosphate
  • Recombinant Fusion Proteins
  • Trans-Activators
  • Endonucleases