Figure 2: A downstream target of protein Kinase B (Akt) is the Forkhead box O or FOXO transcription factors. Phosphorylation of the FOXOs by Akt deactivates them and prevents them from translocating to the nucleus. Dephosphorylated FOXOs translocate to the nucleus where they increase the expression of a variety of genes that suppress skeletal muscle hypertrophy and result in muscle atrophy. They also induce ubiquitin ligases such as muscle ring finger-1 (MuRF1) and atrogin-1 that promote skeletal muscle proteolysis.