Mediator Kinase Substrates in Human Myometrial Stem Cells Revealed by Using Chemical Inhibitors and Quantitative Phosphoproteomics

• DOI: 10.1096/fasebj.2021.35.s1.03798
• Publication Date: 2021-06-11T00:33:05Z
• Authors: Lindsey Barron; Subash Khadka; Thomas Boyer
• Keywords: Mediator; Myometrium; Uterine Fibroids

Uterine fibroids are benign tumors that occur in the myometrium of uterus. Although they benign, represent a significant health problem as affect approximately 70% women and cause pregnancy complications, infertility menstrual disorders. These issues especially concerning uterine reproductive age. To date, non-invasive, long-term treatment options for not available. Thus, need remains to develop non-invasive fibroids. Strikingly, have mutations protein called MED12. MED12 is one 3 proteins constitute Mediator kinase complex. Together, these (MED12, MED13, CYCLIN C CDK8/19) function complex integrate transduce signals RNA polymerase II, thereby regulate transcription response numerous signaling pathways. Interestingly, our lab has previously demonstrated lead loss activity. we hypothesize this activity promotes fibroid formation by dysregulating cellular processes. The goal work was identify substrates phosphorylated progenitor cells, side population (MyoSP) order understand how might promote development In kinase, MyoSP cells were metabolically labeled with either heavy or light stable isotopes treated vehicle specific inhibitor kinase. Mass spectrometry used quantify phosphoproteins from each condition (inhibitor vs. treated). An Empirical Bayes analysis 307 significantly decreased upon inhibitor. Of proteins, 4 (STAT1, TP53BP1, FOXK1, NELFB) further validated direct targets in-vitro assay. conclusion, identifies can be investigated their roles promoting potential novel therapies treat