Isolation And Identification Of The Protein Complex Binding To EGFR 3'untranslated Region

In recent years, the function of 3'untranslated region (UTR) or 5'UTR serves as one of the hotspots in biological research. There are some regulatory elements in the UTR of mRNA sequences, such as the stem loop structure, internal ribosome entry site, and so on. A number of proteins or protein complex may interact with these regulatory elements, which may have an impact on mRNA transcription, processing, nuclear export and subcellular localization, translation and post-translational modifications. The phosphorylation at intracellular specific tyrosine residues of EGFR (epidermal growth factor receptor) can recruit certain signal proteins, such as Shc, Grb2, phospholipase Cγ, and Src. Therefore it can activate the downstream signal pathways. Apparently, EGFR in cells is particularly important.In our study, the method of affinity pull down was used to isolate and identify proteins or protein complex interacting with EGFR 3'UTR from whole cell lysate of HeLa. And then the MALDI-TOF-TOF mass spectrometry was used to analyze these proteins or protein complex in order to clarify the potential function of EGFR 3'UTR in mRNA transport, mRNA stability, subcellular localization or translation.In our study, seven proteins which may interact with EGFR 3'UTR have been identified using mass spectrometry, namely: ILF3 (interleukin enhancer binding factor 3), RHAMM (hyaluronic acid receptor-mediated migration), hnRNP Q (Heterogeneous nuclear ribonucleoprotein Q), hnRNP I, hnRNP A3, hnRNP A1 and hnRNP A2/B1.These proteins we have identified in this study were mostly RBP (RNA binding proteins), which could be involved in maintaining stability, subcellular localization or protein translation of mRNA. The findings in our study will provide some reference valuable to further investigating the regulatory mechanism of EGFR 3'UTR.