Rapid and selective remodeling of a positioned nucleosome during the induction of IL-12 p40 transcription

Immunity. 1999 Dec;11(6):665-75. doi: 10.1016/s1074-7613(00)80141-7.


Nucleosomes are important for gene regulation, but comprehensive studies of nucleosome positioning, remodeling, and transcription factor binding at inducible mammalian promoters have not been reported. We have analyzed the IL-12 p40 promoter, which is induced in macrophages by bacterial products. High-resolution micrococcal nuclease analyses revealed that a positioned nucleosome, nucleosome 1, spans the promoter, with three positioned nucleosomes further upstream. Upon activation, nucleosome 1 was rapidly and selectively remodeled in a protein synthesis-dependent manner. In primary macrophages, IFNgamma synergistically enhanced p40 expression, but little effect on remodeling or promoter occupancy was observed. These results suggest that remodeling complexes are selectively targeted to a single, promoter-encompassing nucleosome and that IFNgamma influences an event that is independent or downstream of remodeling.

Publication types

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

MeSH terms

  • Animals
  • Cell Line
  • Cells, Cultured
  • Gene Expression
  • Interleukin-12 / genetics*
  • Macrophages / cytology
  • Mice
  • Mice, Inbred C57BL
  • Micrococcal Nuclease / metabolism
  • Nucleosomes / metabolism*
  • Promoter Regions, Genetic*
  • Time Factors
  • Transcription, Genetic*


  • Nucleosomes
  • Interleukin-12
  • Micrococcal Nuclease