This entry includes F-box only protein 30 (Fbxo30) []and F-box only protein 40 (Fbxo40) []. Fbxo30 is a ubiquitin ligase required for muscle loss, hence it is also known as muscle ubiquitin ligase of the SCF complex in atrophy-1 (MUSA1) []. Fbxo40 id an E3 ubiquitin ligase that induces IRS1 ubiquitination and breakdown specifically in skeletal muscle cells and only upon IGF1 (insulin-like growth factor 1) stimulation [].
