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Reversible dissociation of coatomer: functional characterization of a beta/delta-coat protein subcomplex

Proc Natl Acad Sci U S A. 1998 Mar 3;95(5):2140-5. doi: 10.1073/pnas.95.5.2140.

Abstract

COPI-coated vesicles mediate protein transport within the early secretory pathway. Their coat consists of ADP ribosylation factor (ARF1, a small guanosine nucleotide binding protein), and coatomer, a cytosolic complex composed of seven subunits, alpha- to zeta-coat proteins (COPs). For coat formation that initiates budding of a vesicle, ARF1 is recruited to the Golgi membrane from the cytosol in its GTP-bound form, and subsequently, coatomer can bind to the membrane. To identify a minimal structure of coatomer capable to bind to Golgi membranes in an ARF1-dependent manner, we have established a procedure to dissociate coatomer under conditions that allow reassociation of the subunits to a complete and functional complex. After dissociation, subunits or subcomplexes can be isolated and may be expected to be functional. Herein we describe isolation of a subcomplex of coatomer consisting of beta- and delta-COPs that is able to bind to Golgi membranes in an ARF1- and GTP-dependent manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP-Ribosylation Factor 1
  • ADP-Ribosylation Factors
  • Animals
  • Coatomer Protein
  • Cytosol / metabolism
  • Dimerization
  • GTP-Binding Proteins / metabolism*
  • Golgi Apparatus / metabolism
  • Guanosine 5'-O-(3-Thiotriphosphate) / pharmacology
  • Guanosine Diphosphate / analogs & derivatives
  • Guanosine Diphosphate / pharmacology
  • Guanosine Triphosphate / metabolism
  • Liver / metabolism
  • Macromolecular Substances
  • Maleic Anhydrides / pharmacology
  • Membrane Proteins / chemistry*
  • Membrane Proteins / isolation & purification
  • Membrane Proteins / metabolism*
  • Microtubule-Associated Proteins / isolation & purification
  • Microtubule-Associated Proteins / metabolism*
  • Rabbits
  • Thionucleotides / pharmacology

Substances

  • Coatomer Protein
  • Macromolecular Substances
  • Maleic Anhydrides
  • Membrane Proteins
  • Microtubule-Associated Proteins
  • Thionucleotides
  • Guanosine Diphosphate
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • 2,3-dimethylmaleic anhydride
  • guanosine 5'-O-(2-thiodiphosphate)
  • Guanosine Triphosphate
  • GTP-Binding Proteins
  • ADP-Ribosylation Factor 1
  • ADP-Ribosylation Factors