Ubiquitination, phosphorylation, and acetylation--triple threat in muscle wasting.

Loss of muscle mass is commonly seen in patients with critical illness and is associated with increased expression of multiple genes controlling protein breakdown. Transcription factors that are activated during muscle wasting include NF-kB and members of the FOXO and C/EBP transcription factor families. The activity of these transcription factors is regulated by multiple posttranslational modifications, including ubiquitination, phosphorylation, and acetylation, providing for a complex and integrated network of regulatory mechanisms in muscle wasting. Targeting posttranslational modifications of transcription factors may prove important in the prevention and treatment of the debilitating consequences of muscle wasting. 2007 Wiley-Liss, Inc.