Browsing by Author "Conlan, Andrea R."

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    Integrated strategy reveals the protein interface between cancer targets Bcl-2 and NAF-1
    (PNAS, 2014) Tamir, Sagi; Rotem-Bamberger, Shahar; Katz, Chen; Morcos, Faruck; Hailey, Kendra L.; Zuris, John A.; Wang, Charles; Conlan, Andrea R.; Lipper, Colin H.; Paddock, Mark L.; Mittler, Ron; Onuchic, José Nelson; Jennings, Patricia A.; Friedler, Assaf; Nechushtai, Rachel; Center for Theoretical Biological Physics
    Life requires orchestrated control of cell proliferation, cell maintenance, and cell death. Involved in these decisions are protein complexes that assimilate a variety of inputs that report on the status of the cell and lead to an output response. Among the proteins involved in this response are nutrient-deprivation autophagy factor-1 (NAF-1)- and Bcl-2. NAF-1 is a homodimeric member of the novel Fe-S protein NEET family, which binds two 2Fe-2S clusters. NAF-1 is an important partner for Bcl-2 at the endoplasmic reticulum to functionally antagonize Beclin 1-dependent autophagy [Chang NC, Nguyen M, Germain M, Shore GC (2010) EMBO J 29 (3):606–618]. We used an integrated approach involving peptide array, deuterium exchange mass spectrometry (DXMS), and functional studies aided by the power of sufficient constraints from direct coupling analysis (DCA) to determine the dominant docked conformation of the NAF-1–Bcl-2 complex. NAF-1 binds to both the pro- and antiapoptotic regions (BH3 and BH4) of Bcl-2, as demonstrated by a nested protein fragment analysis in a peptide array and DXMS analysis. A combination of the solution studies together with a new application of DCA to the eukaryotic proteins NAF-1 and Bcl-2 provided sufficient constraints at amino acid resolution to predict the interaction surfaces and orientation of the protein–protein interactions involved in the docked structure. The specific integrated approach described in this paper provides the first structural information, to our knowledge, for future targeting of the NAF-1–Bcl-2 complex in the regulation of apoptosis/autophagy in cancer biology.
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    NAF-1 and mitoNEET are central to human breast cancer proliferation by maintaining mitochondrial homeostasis and promoting tumor growth
    (National Academy of Sciences, 2013) Sohn, Yang-Sung; Tamir, Sagi; Song, Luhua; Michaeli, Dorit; Matouk, Imad; Conlan, Andrea R.; Harir, Yael; Holt, Sarah H.; Shulaev, Vladimir; Paddock, Mark L.; Hochberg, Abraham; Cabanchick, Ioav Z.; Onuchic, José N.; Jennings, Patricia A.; Nechushtai, Rachel; Mittler, Ron; Center for Theoretical Biological Physics
    Mitochondria are emerging as important players in the transformation process of cells, maintaining the biosynthetic and energetic capacities of cancer cells and serving as one of the primary sites of apoptosis and autophagy regulation. Although several avenues of cancer therapy have focused on mitochondria, progress in developing mitochondria-targeting anticancer drugs nonetheless has been slow, owing to the limited number of known mitochondrial target proteins that link metabolism with autophagy or cell death. Recent studies have demonstrated that two members of the newly discovered family of NEET proteins, NAF-1 (CISD2) and mitoNEET (mNT; CISD1), could play such a role in cancer cells. NAF-1 was shown to be a key player in regulating autophagy, and mNT was proposed to mediate iron and reactive oxygen homeostasis in mitochondria. Here we show that the protein levels of NAF-1 and mNT are elevated in human epithelial breast cancer cells, and that suppressing the level of these proteins using shRNA results in significantly reduced cell proliferation and tumor growth, decreased mitochondrial performance, uncontrolled accumulation of iron and reactive oxygen in mitochondria, and activation of autophagy. Our findings highlight NEET proteins as promising mitochondrial targets for cancer therapy.