Developing methodological approaches for discovering novel pathways is a key challenge in the life science research. Biological pathways are regulated-in higher eukaryotes-by a vast diversity of linear peptide motifs that mediate combinatorial specificity in signal transduction pathways. The E3 ubiquitin ligase component (MDM2) is such a protein that interacts with target proteins containing linear motifs such as p53. Drug leads, such as Nutlin-3, that bind to the MDM2 hydrophobic pocket mimic p53 and can release p53 from MDM2 control and this can lead to cell death. However, these drug leads act allosterically, having agonist effects on MDM2's functions and there are other proteins whose steady state levels can be altered by Nutlin-3. As cell density can alter the proliferation state of cell populations, we examined the impact of Nutlin-3 on levels of newly synthesized proteins using pulse-SILAC mass spectrometry. The data demonstrate that at differing cell densities or population-wide proliferation rates, different newly synthesized proteins dominate the proteome landscape in a Nutlin-3 dependent manner. These data further confirm that the cell state in a population of cells can in turn impact on the MDM2 signalling landscape. This methodology forms a blueprint for biomarker discovery using clinical samples that can detect changes in the synthesis rate of proteins in cell populations treated with specific agents. Broader implications highlight tools that can be used to study allosteric regulation of protein-drug combinations.

• MeSH
• imidazoly * farmakologie   MeSH
• lidé MeSH
• nádorový supresorový protein p53 metabolismus   MeSH
• piperaziny * farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• proteom * metabolismus   MeSH
• proteomika metody   MeSH
• protoonkogenní proteiny c-mdm2 metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Interferon-induced transmembrane proteins IFITM1 and IFITM3 (IFITM1/3) play a role in both RNA viral restriction and in human cancer progression. Using immunohistochemical staining of FFPE tissue, we identified subgroups of cervical cancer patients where IFITM1/3 protein expression is inversely related to metastasis. Guide RNA-CAS9 methods were used to develop an isogenic IFITM1/IFITM3 double null cervical cancer model in order to define dominant pathways triggered by presence or absence of IFITM1/3 signalling. A pulse SILAC methodology identified IRF1, HLA-B, and ISG15 as the most dominating IFNγ inducible proteins whose synthesis was attenuated in the IFITM1/IFITM3 double-null cells. Conversely, SWATH-IP mass spectrometry of ectopically expressed SBP-tagged IFITM1 identified ISG15 and HLA-B as dominant co-associated proteins. ISG15ylation was attenuated in IFNγ treated IFITM1/IFITM3 double-null cells. Proximity ligation assays indicated that HLA-B can interact with IFITM1/3 proteins in parental SiHa cells. Cell surface expression of HLA-B was attenuated in IFNγ treated IFITM1/IFITM3 double-null cells. SWATH-MS proteomic screens in cells treated with IFITM1-targeted siRNA cells resulted in the attenuation of an interferon regulated protein subpopulation including MHC Class I molecules as well as IFITM3, STAT1, B2M, and ISG15. These data have implications for the function of IFITM1/3 in mediating IFNγ stimulated protein synthesis including ISG15ylation and MHC Class I production in cancer cells. The data together suggest that pro-metastatic growth associated with IFITM1/3 negative cervical cancers relates to attenuated expression of MHC Class I molecules that would support tumor immune escape.

• MeSH
• buněčné linie MeSH
• diferenciační antigeny fyziologie   MeSH
• lidé MeSH
• membránové proteiny fyziologie   MeSH
• MHC antigeny I. třídy metabolismus   MeSH
• nádory děložního čípku metabolismus   MeSH
• proteiny vázající RNA fyziologie   MeSH
• proteosyntéza fyziologie   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH