Related Experiment Videos
ADP-ribosylation factor 4 small GTPase mediates epidermal growth factor receptor-dependent phospholipase D2
Sung-Woo Kim1, Masaaki Hayashi, Jeng-Fan Lo
1Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA.
Abstract:
The epidermal growth factor receptor (EGFR) plays a critical role in the development, proliferation, and differentiation of cells of epithelial and mesenchymal origin. These EGFR-dependent cellular processes are mediated by a repertoire of intracellular signaling pathways triggered by the activation of the EGFR cytoplasmic domain, which originates from ligand binding of its extracellular domain. To understand the molecular mechanisms by which the intracellular domain of EGFR transmits mitogenic messages to the downstream signaling pathways, we used the cytoplasmic region of EGFR as bait in yeast two-hybrid screening. We found that ADP-ribosylation factor 4 (ARF4) interacts with the intracellular part of EGFR and mediates the EGF-dependent cellular activation of phospholipase D2 (PLD2) but does not mediate the activation of PLD1. In addition, ARF4-mediated PLD2 activation leads to dramatic activation of the transcription factor activator protein 1 (AP-1), and, importantly, ARF4 activity is required for EGF-induced activation of cellular AP-1. Our findings indicate that ARF4 is a critical molecule that directly regulates cellular PLD2 activity and that this ARF4-mediated PLD2 activation stimulates AP-1-dependent transcription in the EGF-induced cellular response.
Insights
ADP-ribosylation factor 4 (ARF4) interacts with the epidermal growth factor receptor (EGFR) to activate phospholipase D2 (PLD2). This ARF4-PLD2 interaction is crucial for EGF-induced activator protein 1 (AP-1) transcription.
Area of Science:
- Cellular Biology
- Molecular Signaling
- Receptor Tyrosine Kinases
Background:
- Epidermal Growth Factor Receptor (EGFR) signaling is vital for epithelial and mesenchymal cell functions.
- EGFR activation triggers intracellular pathways essential for cell development, proliferation, and differentiation.
- Understanding EGFR's downstream signaling mechanisms is key to deciphering cellular responses.
Purpose of the Study:
- To elucidate the molecular mechanisms of EGFR's intracellular signal transmission.
- To identify novel proteins interacting with the EGFR cytoplasmic domain.
- To investigate the role of identified interactors in EGF-mediated cellular processes.
Main Methods:
- Yeast two-hybrid screening using the EGFR cytoplasmic region as bait.
- Investigating protein-protein interactions between EGFR and potential signaling partners.
- Assessing the impact of identified interactions on downstream signaling pathways like phospholipase D (PLD) and activator protein 1 (AP-1).
Main Results:
- ADP-ribosylation factor 4 (ARF4) was identified as an interacting partner of the EGFR intracellular domain.
- ARF4 mediates the epidermal growth factor (EGF)-dependent activation of phospholipase D2 (PLD2), but not PLD1.
- ARF4 activity is essential for EGF-induced activation of the transcription factor activator protein 1 (AP-1).
Conclusions:
- ARF4 is a critical regulator of cellular PLD2 activity.
- ARF4-mediated PLD2 activation plays a significant role in stimulating AP-1-dependent transcription.
- This study reveals a novel signaling axis: EGFR-ARF4-PLD2-AP-1 in EGF-induced cellular responses.