Work

Characterization of class II and class III ADP-ribosylation factor genes and proteins in Drosophila melanogaster.

Year: 1994

Type: article

Abstract: ADP-ribosylation factors (ARFs) are ubiquitous -20-kDa guanine nucleotide-binding proteins that enhance the ADP-ribosyltransferase activity of cholera toxin and are involved in intracellular vesicular transport.Based on size, phylogenetic analysis, amino acid identity, and gene structure, mammalian ARFs fall into three classes (class I, D l , -2, and -3; class II, ARF4 and -5; class 111, ARFG).A class I ARF had been identified in Drosophila melunogaster.To search for ARFs of other classes in Drosophila, polymerase chain reaction-based techniques were used, resulting in cloning of Drosophila ARF (dARF) I1 and dARF I11 with deduced amino acid sequences similar to those of class I1 and class I11 mammalian A,€ZFs, respectively.The three Drv8Ophih ARF genes map to different chromosomes and the coding regions have different splicing sites.dARF II mRNA, like ARF I mRNA, i s fairly uniformly distributed t~oughout adult flies, whereas dARF III mRNA is significantly more abundant in heads than in legs or bodies.Recombinant dARF I1 and dARF I11 have biochemical and immunological properties similar to those of human A R F B (hA.RF5) and hARF6, respectively.These observations are consistent with the conclusion that the three classes of ARFs are present in non-mammalian as well as mammalian species.~P -n b o s y l a t i o n factors (AFtFs)' are a family of -.ZO-kDa guanine nucleotide-binding proteins that participate in intracellular vesicular trafficking and, in the presence of GTP, enhance the ADP-ribosyltransferase activity of cholera toxin (1-4).ARF proteins, which are highly conserved and ubiquitous in eukaryotic cells (5-lo), have been found associated with Golgi membranes and have been implicated in vesicular transport, including endocytosis and nuclear membrane assembly (3, 11-13).The different mammalian ARFs appear to have different functions and, likely, different intracellular localizations.Consistent with this view, ARF1, -3, and -5 clearly differ in their binding to Golgi (14) as well as i n their dependence on accessory proteins for interaction with Golgi and, perhaps, other cellular membranes (15).ARF, an essential protein in Saccha-*

Source: Journal of Biological Chemistry

DOI: 10.1016/s0021-9258(17)31840-9