Structural basis of interdomain communication in PPARγ

Mosure, S. A.; Munoz-Tello, P.; Kuo, K.-T.; MacTavish, B.; Yu, X.; Scholl, D.; Williams, C. C.; Strutzenberg, T. S.; Bass, J.; Brust, R.; Deniz, A. A.; Griffin, P. R.; Kojetin, D. J.

doi:10.1101/2022.07.13.499031

bioRxiv · 10.1101/2022.07.13.499031

Structural basis of interdomain communication in PPARγ

Mosure, S. A.·Munoz-Tello, P.·Kuo, K.-T.·MacTavish, B.·Yu, X.·Scholl, D.·Williams, C. C.·Strutzenberg, T. S.·Bass, J.·Brust, R.·Deniz, A. A.·Griffin, P. R.·Kojetin, D. J.

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Abstract

The nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR{gamma}) regulates transcription via two activation function (AF) regulatory domains: a ligand-dependent AF-2 coregulator interaction surface within the C-terminal ligand-binding domain (LBD), and an N-terminal disordered AF-1 domain (NTD or A/B region) that functions through poorly understood structural mechanisms. Here, we show the PPAR{gamma} AF-1 contains an evolutionary conserved Trp-Pro motif that undergoes cis/trans isomerization, populating two long-lived conformations that participate in intradomain AF-1 and interdomain interactions including two surfaces in the C-terminal LBD ({beta}-sheet and the AF-2 surface), which are predicted in AlphaFold 3 models but not AlphaFold 2. NMR and chemical crosslinking mass spectrometry show that interdomain interactions occur for soluble isolated AF-1 and LBD proteins, as well as in full-length PPAR{gamma} in a phase separated state. Mutation of the region containing the Trp-Pro motif, which abrogates cis/trans isomerization of this region, impacts LBD interaction and reduces basal PPAR{gamma}-mediated transcription and agonist-dependent activation of PPAR{gamma}. Our findings provide structural insight into published in vitro and cellular studies that reported interdomain functional communication between the PPAR{gamma} AF-1 and LBD suggesting some of these effects may be mediated via AF-1/LBD interactions.

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Mosure, S. A., Munoz-Tello, P., Kuo, K.-T., MacTavish, B., Yu, X., Scholl, D., Williams, C. C., Strutzenberg, T. S., Bass, J., Brust, R., Deniz, A. A., Griffin, P. R., Kojetin, D. J.. 2022-07-13. Structural basis of interdomain communication in PPARγ. https://doi.org/10.1101/2022.07.13.499031

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