EGF and NRG induce phosphorylation of HER3/ERBB3 by EGFR using distinct oligomeric mechanisms.
Heteromeric interactions between the catalytically impaired human epidermal growth factor receptor (HER3/ERBB3) and its catalytically active homologs EGFR and HER2 are essential for their signaling. Different ligands can activate these receptor pairs but lead to divergent signaling outcomes through mechanisms that remain largely unknown. We used stochastic optical reconstruction microscopy (STORM) with pair-correlation analysis to show that EGF and neuregulin (NRG) can induce different extents of HER3 clustering that are dependent on the nature of the coexpressed HER receptor. We found that the presence of these clusters correlated with distinct patterns and mechanisms of receptor phosphorylation. NRG induction of HER3 phosphorylation depended on the formation of the asymmetric kinase dimer with EGFR in the absence of detectable higher-order oligomers. Upon EGF stimulation, HER3 paralleled previously observed EGFR behavior and formed large clusters within which HER3 was phosphorylated via a noncanonical mechanism. HER3 phosphorylation by HER2 in the presence of NRG proceeded through still another mechanism and involved the formation of clusters within which receptor phosphorylation depended on asymmetric kinase dimerization. Our results demonstrate that the higher-order organization of HER receptors is an essential feature of their ligand-induced behavior and plays an essential role in lateral cross-activation of the receptors. We also show that HER receptor ligands exert unique effects on signaling by modulating this behavior.
Cardiovascular Research Institute, University of California, San Francisco, CA 94158.
Bettina
B
van Lengerich
Cardiovascular Research Institute, University of California, San Francisco, CA 94158.
Christopher
C
Agnew
School of Physics and Astronomy, University of Minnesota, Twin Cities, Minneapolis, MN 55455.
Elias M
EM
Puchner
Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158.|Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158.
Bo
B
Huang
Cardiovascular Research Institute, University of California, San Francisco, CA 94158; natalia.jura@ucsf.edu.|Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158.
Natalia
N
Jura
D000818:Animals; D002460:Cell Line; D004815:Epidermal Growth Factor / Q000378:metabolism* / Q000494:pharmacology; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008853:Microscopy / Q000379:methods; D057054:Molecular Imaging / Q000379:methods; D020890:Neuregulin-1 / Q000378:metabolism* / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D055503:Protein Multimerization; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D020893:Receptor, ErbB-3 / Q000235:genetics / Q000378:metabolism*
D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D020890:Neuregulin-1; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; C512478:EGFR protein, human; C508053:ERBB2 protein, human; C581292:ERBB3 protein, human
EGFR activation; HER/ERBB receptors; STORM; receptor clustering; receptor tyrosine kinase signaling