Epidermal growth factor receptors: function modulation by phosphorylation and glycosylation interplay
Afshan Kaleem1, Ishtiaq Ahmad, Daniel C Hoessli
1Institute of Molecular Sciences and Bioinformatics, 28 Nisbet Road, Lahore, Pakistan.
Molecular Biology Reports
|March 15, 2008
Summary
In silico methods predict how protein modifications affect the Epidermal Growth Factor Receptor (EGFR). These predictions reveal how O-GlcNAc modification influences EGFR signaling and endosomal trafficking.
Area of Science:
- Molecular and Cellular Biology
- Biochemistry
- Computational Biology
Background:
- Post-translational modifications (PTMs) transiently alter protein structure and function, making in vivo studies challenging.
- In silico prediction of PTMs aids in understanding these dynamic changes and protein multifunctionality.
- Epidermal Growth Factor Receptor (EGFR) is a key transmembrane protein whose tyrosine kinase activity is regulated by phosphorylation.
Purpose of the Study:
- To investigate potential phosphorylation and O-GlcNAc modification sites on human EGFR using in silico methods.
- To explore the interplay between phosphorylation and O-GlcNAc modifications on EGFR, particularly the 'Yin Yang hypothesis'.
Main Methods:
- Utilized in silico prediction procedures to identify potential phosphorylation sites (Ser, Thr, Tyr) and O-GlcNAc modification sites on EGFR.
- Analyzed the interplay between these modifications at specific residues, including those in the juxtamembrane and catalytic domains.
Main Results:
- Identified multiple phosphorylation sites, including five autophosphorylation sites on Tyr residues.
- Predicted O-GlcNAc modifications on Thr 654 and Ser 1046/1047.
- Proposed that O-GlcNAc modification on Thr 654 may facilitate EGFR transfer to late endosomes, while modification on Ser 1046/1047 might prevent receptor desensitization.
Conclusions:
- The study highlights a complex interplay between EGFR phosphorylation and O-GlcNAc modification.
- These modifications, particularly at Yin Yang sites, significantly modulate EGFR functionality, including endosomal trafficking and signaling.
- In silico predictions provide valuable insights into the dynamic regulation of EGFR activity.
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