guanosine-diphosphate and 2-3-dimethylmaleic-anhydride

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.

Topics: ADP-Ribosylation Factor 1; ADP-Ribosylation Factors; Animals; Coatomer Protein; Cytosol; Dimerization; Golgi Apparatus; GTP-Binding Proteins; Guanosine 5'-O-(3-Thiotriphosphate); Guanosine Diphosphate; Guanosine Triphosphate; Liver; Macromolecular Substances; Maleic Anhydrides; Membrane Proteins; Microtubule-Associated Proteins; Rabbits; Thionucleotides