Evidence that Mediator is essential for Pol II transcription, but is not a required component of the preinitiation complex in vivo

  1. Natalia Petrenko
  2. Yi Jin
  3. Koon Ho Wong
  4. Kevin Struhl  Is a corresponding author
  1. Harvard Medical School Boston, United States
  2. University of Macau, China
8 figures and 1 additional file

Figures

Figure 1 with 3 supplements
Substantial transcription persists upon anchor-away of essential Mediator subunits.

(A) Occupancy of the indicated 3x-HA-FRB tagged Mediator subunit at the indicated enhancers prior to (-Rap) or after (+Rap) being depleted by anchor away. The parental strain containing no …

https://doi.org/10.7554/eLife.28447.002
Figure 1—figure supplement 1
Depletion of Med17 function via the ts mutant or anchor away results in similar transcriptional effects.

(A) Mean Pol II occupancy over ~ 400 transcribed genes prior to and after anchor-away of Med14, Med17, TBP, or the parental strain (WT); data is the same as shown in Figure 1B. Pol II data for the me…

https://doi.org/10.7554/eLife.28447.003
Figure 1—figure supplement 2
Screenshots of Pol II occupancy for the indicated genes for samples analyzed in Figure 1—figure supplement 1A.
https://doi.org/10.7554/eLife.28447.004
Figure 1—figure supplement 3
Pol II occupancy at the indicated constitutive genes in the (A) Med17-AA (± rapamycin) and (B) med17-ts (at permissive temperature and 37°C for 1 or 2 hr) strains.
https://doi.org/10.7554/eLife.28447.005
Figure 2 with 1 supplement
Mediator preferentially affects SAGA-dependent vs.

TFIID-dependent genes. (A) Mean Pol II occupancy for the indicated groups of genes (SAGA or TFIID-dependent) prior to and after anchor-away of Med17, Med14, and Med15, as well as for the parent …

https://doi.org/10.7554/eLife.28447.006
Figure 2—figure supplement 1
Mean Pol II occupancy for the indicated groups of genes (SAGA or TFIID-dependent) prior to and after anchor-away of Sin4 (Med16), Srb6 (Med22), Srb10 (Cdk8), and Med7.

Sequence reads were normalized as counts per million (CPM), and the curves were aligned relative to the transcription start site (TSS).

https://doi.org/10.7554/eLife.28447.007
Figure 3 with 1 supplement
Depletion of Mediator head and middle subunits causes a downstream shift in the Pol II profile.

(A) Overlaid mean Pol II occupancy curves scaled to 100% (maximum levels) after anchor-away of the indicated head and middle subunits of Mediator. (B) Overlaid mean Pol II occupancy curves scaled to …

https://doi.org/10.7554/eLife.28447.008
Figure 3—figure supplement 1
Overlaid mean Pol II occupancy curves scaled to 100% after anchor-away of TBP, as well as for the parent strain (WT) before and after rapamycin addition.

Sequence reads were normalized as counts per million (CPM), and the curves were aligned relative to the transcription start site (TSS).

https://doi.org/10.7554/eLife.28447.009
Figure 4 with 2 supplements
Pol II transcription can occur from preinitiation complexes lacking Mediator.

(A) Pol II occupancy in the coding regions and Mediator subunits at the promoters of the CCW12 and TEF1 genes, before or after anchor-away of Med17, Kin28, or both simultaneously. (B) TBP and TFIIB …

https://doi.org/10.7554/eLife.28447.010
Figure 4—figure supplement 1
Pol II transcription can occur from preinitiation complexes lacking Mediator.

(A) Occupancy of Pol II in the coding regions, and Mediator (Med8 and Med22 subunits), TBP, and TFIIB subunits at the promoters of the inducible HSP12, HSP82, and CUP1 genes before or after …

https://doi.org/10.7554/eLife.28447.011
Figure 4—figure supplement 2
Pol II transcription can occur from preinitiation complexes lacking Mediator.

Occupancy of Mediator (Med8 and Med22 subunits), TBP, and TFIIB at the promoters (A) SED1 and (B) PMA1 in the presence of absence of rapamycin and the presence or absence of a heat shock at 39°C.

https://doi.org/10.7554/eLife.28447.012
Depletion of TBP does not alter the composition of the preinitiation complex.

(A) Occupancy of Pol II in the coding regions, and Med22, TBP, and TFIIB at the promoters of the indicated genes before or after simultaneous depletion of TBP and Kin28. (B) Occupancy of Pol II in …

https://doi.org/10.7554/eLife.28447.013
Figure 6 with 1 supplement
Mediator is important, but not essential, for serine 5 phosphorylation of the Pol II CTD.

The ratio of S5-phosphorylated CTD levels relative to total Rpb1 levels at the promoters of the indicated genes, depletion of the indicated proteins or the control strain (WT).

https://doi.org/10.7554/eLife.28447.014
Figure 6—figure supplement 1
The ratio of S5-phosphorylated CTD levels relative to Rpb1 levels at the transcription stop sites of the indicated genes prior to or after Kin28 anchor-away, Med17 anchor-away, or a double anchor-away of Med7 and Med22, as well as in the parent strain (WT).
https://doi.org/10.7554/eLife.28447.015
Pol II transcription is virtually eliminated when Mediator head, middle, and tail modules are simultaneously inactivated.

(A) Pol II occupancy in the coding regions of the indicated constitutive and inducible genes for the parent strain (WT) and ‘triple’ mutant strain, in which the tail module is inactivated via …

https://doi.org/10.7554/eLife.28447.016
Growth of Mediator depletion strains.

(A) growth on YPD (2.5 days) in the presence or absence rapamycin upon anchor-away mediated depletion of the Mediator subunit (light blue shading) or general transcription factor (dark blue shading) …

https://doi.org/10.7554/eLife.28447.017

Additional files

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