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Review
. 2017 Nov;42(11):850-861.
doi: 10.1016/j.tibs.2017.09.001. Epub 2017 Sep 27.

Sharing the SAGA

Dominique Helmlinger  1 , László Tora  2
Affiliations
Review

Sharing the SAGA

Dominique Helmlinger et al. Trends Biochem Sci. 2017 Nov.

Abstract

Transcription initiation is a major regulatory step in eukaryotic gene expression. Co-activators establish transcriptionally competent promoter architectures and chromatin signatures to allow the formation of the pre-initiation complex (PIC), comprising RNA polymerase II (Pol II) and general transcription factors (GTFs). Many GTFs and co-activators are multisubunit complexes, in which individual components are organized into functional modules carrying specific activities. Recent advances in affinity purification and mass spectrometry analyses have revealed that these complexes often share functional modules, rather than containing unique components. This observation appears remarkably prevalent for chromatin-modifying and remodeling complexes. Here, we use the modular organization of the evolutionary conserved Spt-Ada-Gcn5 acetyltransferase (SAGA) complex as a paradigm to illustrate how co-activators share and combine a relatively limited set of functional tools.

Keywords: assembly; chromatin; functional module; multisubunit complex; protein–protein interaction; transcription.

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Figures

Figure 1
Figure 1. Schematic illustration of the composition of SAGA and the sharing of its components with other regulatory complexes.
For simplification, only human subunit names are shown, unless otherwise indicated (scSpt8 and scTBP). SAGA subunits are organized into structurally and functionally distinct modules that are shared with other regulatory complexes. Shared subunits are drawn identical between distinct complexes. Related subunits are drawn using the same colour, but with a black edge. The histone-acetyltransferase (HAT) module, depicted in red, is shared with the S. cerevisiae ADA complex (scADA) and the metazoan ATAC complexes. Several components of the core structural module, in green, form the core of the general transcription factor IID (TFIID). In S. cerevisiae, Spt3 and Spt8 recruit TBP to SAGA, but it is unclear whether such a functional module exists in metazoans, in which SUPT3H might rather be part of SAGA core structural module. The splicing module, in purple, is shared with the human SF3B complex, which associates with the U2 snRNP to initiate splicing. The transcription factor (TF) binding subunit TRRAP, in orange, recruits both the SAGA and yNuA4/hTIP60 complexes to promoters. Finally, the deubiquitinase (DUB) module, in blue, shares both ATXN7L3 and ENY2 with either of the two USP22 paralogous deubiquitinases, USP27x and USP51. In addition, the DUB module component ENY2 is shared with the mRNA export factor TREX-2.
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References

    1. Yun M, et al. Readers of histone modifications. Cell Res. 2011;21:564–578. - PMC - PubMed
    1. Bannister AJ, Kouzarides T. Regulation of chromatin by histone modifications. Cell Res. 2011;21:381–395. - PMC - PubMed
    1. Cler E, et al. Recent advances in understanding the structure and function of general transcription factor TFIID. Cell Mol Life Sci. 2009;66:2123–2134. - PMC - PubMed
    1. Muller F, et al. Developmental regulation of transcription initiation: more than just changing the actors. Current opinion in genetics & development. 2010;20:533–540. - PubMed
    1. Goodrich JA, Tjian R. Unexpected roles for core promoter recognition factors in cell-type-specific transcription and gene regulation. Nature reviews Genetics. 2010;11:549–558. - PMC - PubMed

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