Program

Oral Sessions

Day 2, May 16（Wed.）　10:25-10:45　Room C (Seiun 2)

2C-O1-P-1025　　PDF

Improvement of comprehensive phosphotyrosine proteomics

(NIBIOHN)
^oYuichi Abe, Asa Tada, Junko Isoyama, Maiko Nagano, Takahisa Kuga, Ayako Sato, Jun Adachi, Takeshi Tomonaga

The phosphosignaling acts as regulator of cell proliferation, differentiation, environmental response. The failure of phosphosignaling, especially phosphotyrosine signaling, leads to oncogenesis. Thus, tyrosine kinase family is an important target in cancer therapy. Comprehensive phosphotyrosine proteomics would greatly contribute the discovery of novel cancer therapeutic targets and the establishment of efficient therapeutic strategies.
When performing large-scale phosphoproteomics using the IMAC, MOAC, and HAMMOC method, the ratio of phosphorylated tyrosine sites in the identified phosphorylated peptides is usually limited less than 1%. In order to improve the identification number of phosphotyrosine sites, previous study performed immunoprecipitation with antibody against phosphotyrosine site. In this study, we tried to improve the identification number of phosphorylated tyrosine by examining several conditions during immunoprecipitation and LC-MSMS analysis.
As a result, we succeeded in identifying more than 1,000 phosphotyrosine sites per sample. Also, we measured modulation of phosphotyrosine signaling in cells with or without treatment of tyrosine kinase inhibitor. Furthermore, kinome analysis was performed by combining phospho-proteomics method by Fe-IMAC with optimized tyrosine phosphorylation proteomics method.
Our phosphotyrosine proteomics is expected to lead to the identification of novel therapeutic targets and diagnostic markers for drug sensitivity.