Abstract Phospholipase D1 (PLD1) is known to be activated by ADP- ribosylation factor 1 (ARF1). We report here that ARF1 co-immunoprecipitates with PLD1 and that the ARF1-dependent PLD activation is induced by the direct interaction between ARF1 and PLD1. We found that Ra1A, another member of the small GTP-binding proteins, synergistically enhances the ARF1-dependent PLD activity with an EC50 of about 30 nM. Using in vitro binding assay, we show that ARF1 and Ra1A directly interact with different sites of PLD1. The results suggest that the independent interactions of Ra1A and ARF1 with PLD1 are responsible for the synergistic activation.
Bibliographical noteFunding Information:
This work is supported in part by the program of the Ministry of Education (BSRI-97-4434) and by the `1997 Good Health R&D Project' of the Ministry of Health and Welfare from the Republic of Korea.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology
- Cell Biology