A mammalian mediator subunit that shares properties with saccharomyces cerevisiae mediator subunit CSE2




Tomomori-Sato, Chieri
Sato, Shigeo
Parmely, Tari J.
Banks, Charles A.S.
Sorokina, Irina
Florens, Laurence
Zybailov, Boris
Washburn, Michael P.
Brower, Christopher S.
Conaway, Ronald C.

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The multiprotein Mediator complex is a coactivator required for activation of RNA polymerase II transcription by DNA bound transcription factors. We previously identified and partially purified a mammalian Mediator complex from rat liver nuclei (Brower, C.S., Sato, S., Tomomori-Sato, C., Kamura, T., Pause, A., Stearman, R., Klausner, R.D., Malik, S., Lane, W.S., Sorokina, I., Roeder, R.G., Conaway, J.W., and Conaway, R.C. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 10353–10358). Analysis by tandem mass spectrometry of proteins present in the most highly purified rat Mediator fractions led to the identification of a collection of new mammalian Mediator subunits, as well as several potential Mediator subunits including a previously uncharacterized protein encoded by the FLJ10193 open reading frame. In this study, we present direct biochemical evidence that the FLJ10193 protein, which we designate Med25, is a bona fide subunit of the mammalian Mediator complex. In addition, we present evidence that Med25 shares structural and functional properties with Saccharomyces cerevisiae Mediator subunit Cse2 and may be a mammalian Cse2 ortholog. Taken together, our findings identify a novel mammalian Mediator subunit and shed new light on the architecture of the mammalian Mediator complex.


Article originally published by Journal of Biological Chemistry, 279(7). English. Published online 2004. https://doi.org/10.1074/jbc.m312523200.


Tandem mass spectrometry, Thyroid hormone receptor-associated protein, High pressure liquid chromatography


This is the published version of an article that is available at https://doi.org/10.1074/jbc.m312523200. Recommended citation: Tomomori-Sato, C., Sato, S., Parmely, T. J., Banks, C. A. S., Sorokina, I., Florens, L., Zybailov, B., Washburn, M. P., Brower, C. S., Conaway, R. C., & Conaway, J. W. (2004). A mammalian mediator subunit that shares properties with saccharomyces cerevisiae mediator subunit CSE2. Journal of Biological Chemistry, 279(7), 5846–5851. This item has been deposited in accordance with publisher copyright and licensing terms and with the author’s permission.