This proposal requests funds to purchase a triple quadrupole mass spectrometer to support than 12 NIH-funded projects led by 9 principal investigators at the Fred Hutchinson Cancer Research Center (FHCRC) as well as Cancer Consortium members from the University of Washington and Children's Hospital. Projects that will benefit from this instrumentation span a variety of areas important for cancer research. Specifically the instrument will be used to understand the role of serine/threonine phosphorylation events in cell-cell communication;determine the importance of tyrosine phosphorylation events in Src kinase-modulated signaling pathways;measure the relationship between protein ubiquitination pathways and protein quality control;validate serum biomarkers in cancers of the breast, pancreas, prostate, ovary, and lung;and measure the serum half life of tumor "painting" reagents. Current mass spectrometry instrumentation at the Center (ion- trap and ion-trap/hybrid instruments) is used primarily for large proteomic profiling (e.g., discovery) studies, but is not well suited for applications that require experimental workflows that target specific molecules. Specifically, these projects require an instrument capable of performing 1) qualitative assays of specific protein modifications using precursor ion scanning and 2) highly-sensitive multiplexed quantitative assays for large numbers (100s to 1000s) of peptides in serum using Single/Multiple Reaction Monitoring (S/MRM). The triple quadrupole mass spectrometer is uniquely suited to meet these requirements. Current NIH-funded research with these requirements will demand over 2416 injections onto this instrument per year, or over 87% utilization. If awarded, the triple quadrupole instrument would be operated by the FHCRC Proteomics Shared Resource, where expertise exists to operate, maintain, and manage the instrument, and policies exist to ensure it is accessible to the entire FHCRC and Consortium community, as well as other NIH-funded investigators in the region. Moreover, the FHCRC supports a Computational Proteomics Shared Resource, managed by Center faculty who have expertise and experience to support the computational infrastructure needed to make use of the data generated by the instrument. The requested instrument will address both immediate and future needs of the user community and support NIH-funded research at the FHCRC. PUBLIC HEALTH RELEVANCE: Protein analysis by mass spectrometry is one of the most powerful and expanding analytical tools in cutting-edge biomedical research, and access to proteomics technology is critical to fully understand the biological basis of human disease and to discover and validate protein biomarkers to better diagnose disease and monitor treatment efficacy. The triple quadrupole mass spectrometer requested in this application will provide NIH funded researchers at the Fred Hutchinson Cancer Research Center critically important proteomics data for 1) the early detection of ovarian, lung, pancreatic, prostate and breast cancer through biomarker validation, 2) the development of sensitive assays to detect cancer imaging agents, and 3) the sensitive detection of protein modifications associated with signal transduction pathways, chromatin biology, protein quality control, and cell-cell communication. Ultimately, data produced from this instrument will lead to a better understanding of cancer at the molecular level and improved detection and outcomes for people afflicted with cancer.