Nucleosome linking number change controlled by acetylation of histones H3 and H4.

V G Norton,K W Marvin,P Yau,E M Bradbury

doi:10.1016/s0021-9258(17)45450-0

V G Norton, K W Marvin + Show 2 more

Open Access

https://doi.org/10.1016/s0021-9258(17)45450-0

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Abstract

High levels of acetylation of lysines in the amino-terminal domains of all four core histones, H2A, H2B, H3, and H4, have been shown to reduce the linking number change per nucleosome core particle in reconstituted minichromosomes (Norton, V. G., Imai, B. S., Yau, P., and Bradbury, E. M. (1989) Cell 57, 449-457). Because there is evidence to suggest that the acetylations of H3 and H4 have functions that are distinct from those of H2A and H2B, we have determined the nucleosome core particle linking number change in minichromosomes containing fully acetylated H3 and H4 and very low levels of acetylation in H2A and H2B. This linking number change was -0.81 +/- 0.05, in close agreement with the linking number change for hyperacetylated nucleosome core particles which contain high levels of acetylation in all four core histones (approximately 70% of full acetylation in H3 and H4). Therefore, high levels of acetylation of H3 and H4 alone are responsible for the reduction in the linking number change per nucleosome core particle.

Highlights

Of Biological Chemistry, School of Medicine, University of California, Davis, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
This reversible modification of lysine groups in the amino-terminal domains of the four core histones has been correlated with cellular processes such as replication (Z), spermiogenesis [3, 4], changes in transcriptional activity associated with the cell cycle [2, 5], regeneration [6], differentiation [7], and stimulation by hormones and growth factors [8,9,10,11]
Entiation in duck erythrocytes [7], that acetylation of H4 accounts for 50-60% of the increase in histone acetylation associated with increased transcriptional activity in regenerating rat liver [6], and that hyperacetylation of H4 appears to be an initial step in spermiogenesis in rainbow trout [13]

Summary

PROCEDURES

A portion of “Experimental Procedures” can be found in the “Miniprint” of the accompanyingpaper [23]. ~~207-18 DNA and reformed octamers were mixed in 2 M NaCl. 20 mM Tris-HCl. 8.0, 1 mM EDTA, 10 mM PME, and 0.1 mM PMSF, and the mixture was dialyzed against a solution of 2 M NaCl, 5 M urea, 20 mM. The linking number change per nucleosome core particle reconstituted from control reformed octamers was found to be -1.04 + 0.03, in close agreement with the value previously determined for control nucleosome core particles reconstituted from intact histone octamers (l), indicating that the octamers themselves are properly formed.

RESULTS

Fully acetylated

DISCUSSION