Item type: | Article | ||||
---|---|---|---|---|---|
Journal or Publication Title: | Journal of Biological Chemistry | ||||
Publisher: | AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC | ||||
Place of Publication: | BETHESDA | ||||
Volume: | 294 | ||||
Number of Issue or Book Chapter: | 9 | ||||
Page Range: | pp. 3294-3310 | ||||
Date: | 2019 | ||||
Institutions: | Medicine > Lehrstuhl für Innere Medizin III (Hämatologie und Internistische Onkologie) Leibniz Institute for Immunotherapy (LIT) Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Biochemie III > Prof. Dr. Gernot Längst Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Cell Cycle Control > Prof. Dr. Frank Sprenger Chemistry and Pharmacy > Institut für Analytische Chemie, Chemo- und Biosensorik > Bioanalytik und Biosensorik (Prof. Joachim Wegener) | ||||
Identification Number: |
| ||||
Keywords: | SWI-SNF COMPLEX; ATP-HYDROLYSIS; RETINOBLASTOMA PROTEIN; TUMOR-SUPPRESSOR; DNA; BINDING; CYCLE; IDENTIFICATION; HELICASES; GROWTH; cell cycle; chromatin remodeling; ATPase; nucleosome; tumor suppressor gene; ATP; cell proliferation; ATPase domain; BRG1; SF2 helicase family | ||||
Dewey Decimal Classification: | 500 Science > 540 Chemistry & allied sciences 500 Science > 570 Life sciences 600 Technology > 610 Medical sciences Medicine | ||||
Status: | Published | ||||
Refereed: | Yes, this version has been refereed | ||||
Created at the University of Regensburg: | Yes | ||||
Item ID: | 48908 |
Abstract
The Snf2 proteins, comprising 53 different enzymes in humans, belong to the SF2 family. Many Snf2 enzymes possess chromatin-remodeling activity, requiring a functional ATPase domain consisting of conserved motifs named Q and I-VII. These motifs form two recA-like domains, creating an ATP-binding pocket. Little is known about the function of the conserved motifs in chromatin-remodeling enzymes. ...

Abstract
The Snf2 proteins, comprising 53 different enzymes in humans, belong to the SF2 family. Many Snf2 enzymes possess chromatin-remodeling activity, requiring a functional ATPase domain consisting of conserved motifs named Q and I-VII. These motifs form two recA-like domains, creating an ATP-binding pocket. Little is known about the function of the conserved motifs in chromatin-remodeling enzymes. Here, we characterized the function of the Q and I (Walker I) motifs in hBRG1 (SMARCA4). The motifs are in close proximity to the bound ATP, suggesting a role in nucleotide binding and/or hydrolysis. Unexpectedly, when substituting the conserved residues Gln(758) (Q motif) or Lys(785) (I motif) of both motifs, all variants still bound ATP and exhibited basal ATPase activity similar to that of wildtype BRG1 (wtBRG1). However, all mutants lost the nucleosome-dependent stimulation of the ATPase domain. Their chromatin-remodeling rates were impaired accordingly, but nucleosome binding was retained and still comparable with that of wtBRG1. Interestingly, a cancer-relevant substitution, L754F (Q motif), displayed defects similar to the Gln(758) variant(s), arguing for a comparable loss of function. Because we excluded a mutual interference of ATP and nucleosome binding, we postulate that both motifs stimulate the ATPase and chromatin-remodeling activities upon binding of BRG1 to nucleosomes, probably via allosteric mechanisms. Furthermore, mutations of both motifs similarly affect the enzymatic functionality of BRG1 in vitro and in living cells. Of note, in BRG1-deficient H1299 cells, exogenously expressed wtBRG1, but not BRG1 Q758A and BRG1 K785R, exhibited a tumor suppressor-like function.
Metadata last modified: 03 Sep 2021 10:04