Arfaptin 1, a putative cytosolic target protein of ADP-ribosylation factor, is recruited to Golgi membranes.

ADP-ribosylation factors (ARFs) have been implicated in vesicle transport in the Golgi complex. Employing yeast two-hybrid screening of an HL60 cDNA library using a constitutively active mutant of ARF3 (ARF3.Q71L), as a probe, we have identified a cDNA encoding a novel protein with a calculated molecular mass of 38.6 kDa, ...
which we have named arfaptin 1. The mRNA of arfaptin 1 was ubiquitously expressed, and recombinant arfaptin 1 bound preferentially to class I ARFs, especially ARF1, but only in the GTP-bound form. The interactions were independent of myristoylation of ARF. Arfaptin 1 in cytosol was recruited to Golgi membranes by ARF in a guanosine 5'-O-(3-thiotriphosphate)-dependent and brefeldin A-sensitive manner. When expressed in COS cells, arfaptin 1 was localized to the Golgi complex. The yeast two-hybrid system yielded another clone, which encoded a putative protein, which we have named arfaptin 2. This consisted of the same number of amino acids as arfaptin 1 and was 60% identical to it. Arfaptin 2 was also ubiquitously expressed and bound to the GTP-, but not GDP-liganded form of class I ARFs, especially ARF1. These results suggest that arfaptins 1 and 2 may be direct target proteins of class 1 ARFs. Arfaptin 1 may be involved in Golgi function along with ARF1.
Mesh Terms:
ADP-Ribosylation Factor 1, ADP-Ribosylation Factors, Adaptor Proteins, Signal Transducing, Adenosine Diphosphate Ribose, Adenylate Cyclase, Amino Acid Sequence, Animals, Base Sequence, Blotting, Western, COS Cells, Carrier Proteins, DNA, Complementary, GTP-Binding Proteins, Golgi Apparatus, Guanosine 5'-O-(3-Thiotriphosphate), Guanosine Triphosphate, HL-60 Cells, Humans, Molecular Sequence Data, Open Reading Frames, Receptors, Adrenergic, beta, Sequence Homology, Amino Acid
J. Biol. Chem.
Date: Feb. 28, 1997
Download Curated Data For This Publication
310
Switch View:
  • Interactions 8