ARF1(2-17) does not specifically interact with ARF1-dependent pathways. Inhibition by peptide of phospholipases C beta, D and exocytosis in HL60 cells.
The small GTP-binding protein ARF has been shown recently to regulate phospholipase D (PLD). In order to investigate the role of ARF proteins in regulated exocytosis, we have used the N-terminal peptide ARF1(2-17) of the ARF1 protein. ARF1 reconstituted PLD activity in cytosol-depleted HL60 cells was inhibited by ARF1(2-17). In the presence of endogenous cytosol, ARF1(2-17) also inhibited GTP-gamma-S-stimulated PLD activity and exocytosis. Mastoparan Politses jadwagae and mastoparan Vespula lewisii which exhibit similar structural properties to ARF1(2-17) also inhibited GTP-gamma-S-stimulated PLD and exocytosis. GTP-gamma-S-stimulated phospholipase C-beta (PLC-beta) was also inhibited by ARF(2-17) and mastoparan. In cytosol-depleted HL60 cells, the ARF(2-17) inhibited the reconstitution of GTP-gamma-S-stimulated PLC-beta activity with exogenously-added PLC-beta 1 and phosphatidylinositol transfer protein. We conclude that the widely-used ARF1(2-17) peptide inhibits both ARF-independent (i.e. PLC-beta) and ARF-dependent pathways (i.e. PLD) and therefore cannot be regarded as a specific inhibitor of ARF function.
Fensome
A
A
Department of Physiology, University College London, UK.
Cunningham
E
E
Troung
O
O
Cockcroft
S
S
D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors; D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D005089:Exocytosis / Q000187:drug effects*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism*; D010455:Peptides; D054799:Phospholipase C beta; D010739:Phospholipase D / Q000037:antagonists & inhibitors*; D013301:Streptolysins / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors*; D014862:Wasp Venoms / Q000494:pharmacology
D001426:Bacterial Proteins; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes; D010446:Peptide Fragments; D010455:Peptides; D013301:Streptolysins; D014862:Wasp Venoms; C025964:streptolysin O; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C037500:mastoparan; D010738:Type C Phospholipases; D054799:Phospholipase C beta; D010739:Phospholipase D; D019204:GTP-Binding Proteins; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors