Research Article
Guang-Rong Yan, Nan-Peng Ch
Abstract
Signaling molecules in signaling pathways proceed to be phosphorylated in the signal transmission from membrane receptors to nuclus. Dysregulated phosphorylation has been implicated in a variety of human diseases including cancer. In this study, we combined SDS-PAGE prefractionation, TiO2 phosphopeptide enrichment and LC-MS/MS technologies to identify the phosphoproteins and their regulatory sites in human gastric cancer cells. Totally 282 phosphorylation sites, corresponding to 245 unique peptides and 161 different proteins, were identified after the evaluation of ambiguous phosphosites. Among them, the phosphorylation of 109 (38.7%) sites and 36 (22.4%) proteins has not been previously reported. It was found that EGFR-ERK1/2 signaling network was mainly involved in the phosphorylation regulation of the identified proteins, suggestting that EGFR-ERK1/2 pathway plays a critical role in the network controlling gastric cancer cell process, and thus may be a drug target of anti-gastric cancer.