Reduce, Retain, Recycle: Mechanisms for Promoting Histone Protein Degradation versus Stability and Retention

ABSTRACT

The eukaryotic genome is packaged into chromatin. The nucleosome, the basic unit of chromatin, is composed of DNA coiled around a histone octamer. Histones are among the longest-lived protein species in mammalian cells due to their thermodynamic stability and their associations with DNA and histone chaperones. Histone metabolism plays an integral role in homeostasis. While histones are largely stable, the degradation of histone proteins is necessary under specific conditions. Here, we review the physiological and cellular contexts that promote histone degradation. We describe specific known mechanisms that drive histone proteolysis. Finally, we discuss the importance of histone degradation and regulation of histone supply for organismal and cellular fitness.

KEYWORDS:

• DNA replication
• chaperone
• chromatin
• histone
• nucleosome
• nucleus
• posttranslational modification
• transcription

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Article of Significant Interest in This Issue

ACKNOWLEDGMENTS

We thank Alexander S. Lee for careful reading of the manuscript and the Foltz laboratory for their contributions.

D.R.F. is supported by a Zell Scholarship from the Robert H. Lurie Comprehensive Cancer Center, Northwestern University, and by the NIGMS (R01GM111907) and NCI (U01CA260699).