Quantitative Phosphoproteomics Analysis of ERBB3/ERBB4 Signaling

Area of Science:

• Cellular Biology
• Molecular Signaling
• Cancer Research

Background:

• The epidermal growth factor receptor (EGFR/ERBB) family plays crucial roles in cellular processes, with EGFR signaling well-understood.
• Signal transduction via ERBB3/ERBB4 heterodimers remains less characterized.
• Understanding ERBB3/ERBB4 signaling is vital for cancer research and therapeutic development.

Purpose of the Study:

• To investigate the signaling pathways mediated by ERBB3/ERBB4 heterodimers.
• To establish a defined cellular model for studying ERBB3/ERBB4 signaling.
• To perform a global phosphoproteomics analysis of ERBB3/ERBB4 signaling.

Main Methods:

• Generated isogenic mouse Ba/F3 cells expressing ERBB3/ERBB4 or ERBB4 alone.
• Utilized quantitative mass spectrometry (MS) with mTRAQ labeling for phosphoproteomics.
• Performed differential isotope labeling, peptide separation, and phosphopeptide enrichment.

Main Results:

• Identified 9686 phosphorylation sites, with 492 significantly altered upon neuregulin-1 (NRG1) treatment in ERBB3/ERBB4 cells.
• Confirmed regulation of MAPK and Akt pathways, and identified links to cytoskeletal and nuclear functions.
• ERBB3 broadly enhanced phosphoproteome regulation, rather than triggering specific pathways, in NRG1-stimulated cells.

Conclusions:

• This study provides the first global phosphoproteomic landscape of ERBB3/ERBB4 signaling.
• ERBB3 co-expression significantly enhances cell proliferation and broadly impacts signaling in response to NRG1.
• The findings offer numerous starting points for future mechanistic studies of ERBB3/ERBB4 signaling in normal and cancer tissues.