Regulation of Rvb1/Rvb2 by a Domain within the INO80 Chromatin Remodeling Complex Implicates the Yeast Rvbs as Protein Assembly Chaperones

Coral Y Zhou; Caitlin I Stoddard; Jonathan B Johnston; Michael J Trnka; Ignacia Echeverria; Eugene Palovcak; Andrej Sali; Alma L Burlingame; Yifan Cheng; Geeta J Narlikar

doi:10.1016/j.celrep.2017.05.029

Regulation of Rvb1/Rvb2 by a Domain within the INO80 Chromatin Remodeling Complex Implicates the Yeast Rvbs as Protein Assembly Chaperones

Cell Rep. 2017 Jun 6;19(10):2033-2044. doi: 10.1016/j.celrep.2017.05.029.

Authors

Affiliations

¹ Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA.
² Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA.
³ Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA.
⁴ Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA.
⁵ Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute of Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94158, USA.
⁶ Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
⁷ Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA. Electronic address: geeta.narlikar@ucsf.edu.

Abstract

The hexameric AAA+ ATPases Rvb1 and Rvb2 (Rvbs) are essential for diverse processes ranging from metabolic signaling to chromatin remodeling, but their functions are unknown. While originally thought to act as helicases, recent proposals suggest that Rvbs act as protein assembly chaperones. However, experimental evidence for chaperone-like behavior is lacking. Here, we identify a potent protein activator of the Rvbs, a domain in the Ino80 ATPase subunit of the INO80 chromatin-remodeling complex, termed Ino80INS. Ino80INS stimulates Rvbs' ATPase activity by 16-fold while concomitantly promoting their dodecamerization. Using mass spectrometry, cryo-EM, and integrative modeling, we find that Ino80INS binds asymmetrically along the dodecamerization interface, resulting in a conformationally flexible dodecamer that collapses into hexamers upon ATP addition. Our results demonstrate the chaperone-like potential of Rvb1/Rvb2 and suggest a model where binding of multiple clients such as Ino80 stimulates ATP-driven cycling between hexamers and dodecamers, providing iterative opportunities for correct subunit assembly.

Keywords: AAA+ ATPase; INO80; RuvBL1; RuvBL2; Rvb1; Rvb2; chaperone; chromatin remodeling; pontin; reptin.

MeSH terms

Molecular Chaperones / chemistry*
Molecular Chaperones / genetics
Molecular Chaperones / metabolism
Protein Domains
Protein Structure, Quaternary
Saccharomyces cerevisiae / chemistry*
Saccharomyces cerevisiae / genetics
Saccharomyces cerevisiae / metabolism
Saccharomyces cerevisiae Proteins / chemistry*
Saccharomyces cerevisiae Proteins / genetics
Saccharomyces cerevisiae Proteins / metabolism

Substances

INO80 complex, S cerevisiae
Molecular Chaperones
Saccharomyces cerevisiae Proteins

Abstract

MeSH terms

Substances

Grants and funding