Human ACF1 alters the remodeling strategy of SNF2h

J Biol Chem. 2006 Sep 29;281(39):28636-47. doi: 10.1074/jbc.M603008200. Epub 2006 Jul 29.

Abstract

The human ACF chromatin-remodeling complex (hACF) contains the ATPase motor protein SNF2h and the non-catalytic hACF1 subunit. Here, we have compared the ability of SNF2h and a reconstituted hACF complex containing both SNF2h and hACF1 to remodel a series of nucleosomes containing different lengths of DNA overhang. Both SNF2h and hACF functioned in a manner consistent with sliding a canonical nucleosome. However, the non-catalytic subunit, hACF1, altered the remodeling properties of SNF2h by changing the nature of the requirement for a DNA overhang in the nucleosomal substrate and altering the DNA accessibility profile of the remodeled products. Surprisingly, addition of hACF1 to SNF2h increased the amount of DNA overhang needed to observe measurable amounts of DNA accessibility, but decreased the amount of overhang needed for a measurable binding interaction. We propose that these hACF1 functions might contribute to making the hACF complex more efficient at nucleosome spacing compared with SNF2h. In contrast, the SWI/SNF complex and its ATPase subunit BRG1 generated DNA accessibility profiles that were similar to each other, but different significantly from those of hACF and SNF2h. Thus, we observed divergent remodeling behaviors in these two remodeling families and found that the manner in which hACF1 alters the remodeling behavior of the ATPase is not shared by SWI/SNF subunits.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adenosine Triphosphatases / chemistry*
  • Adenosine Triphosphate / chemistry
  • Catalytic Domain
  • Chromatin / chemistry
  • Chromosomal Proteins, Non-Histone / chemistry*
  • DNA / chemistry
  • Dose-Response Relationship, Drug
  • Humans
  • Kinetics
  • Micrococcal Nuclease / metabolism
  • Nucleosomes / metabolism
  • Protein Binding
  • Protein Structure, Tertiary
  • Substrate Specificity
  • Transcription Factors / chemistry
  • Transcription Factors / physiology*

Substances

  • BAZ1A protein, human
  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • Nucleosomes
  • Transcription Factors
  • Adenosine Triphosphate
  • DNA
  • Micrococcal Nuclease
  • Adenosine Triphosphatases
  • SMARCA5 protein, human