First Author | Maragno AL | Year | 2006 |
Journal | Biochim Biophys Acta | Volume | 1760 |
Issue | 6 | Pages | 966-72 |
PubMed ID | 16714087 | Mgi Jnum | J:163134 |
Mgi Id | MGI:4821074 | Doi | 10.1016/j.bbagen.2006.03.020 |
Citation | Maragno AL, et al. (2006) FBXO25, an F-box protein homologue of atrogin-1, is not induced in atrophying muscle. Biochim Biophys Acta 1760(6):966-72 |
abstractText | Atrogin-1/MAFbx/FBXO32 is a muscle-specific ubiquitin-ligase (E3) that is dramatically increased in atrophying muscle. Here, we have investigated the functional relationship between atrogin-1 and FBXO25 which shares 65% amino acid identity. Using a RT-PCR, we demonstrated that FBXO25 is highly expressed in brain, kidney, and intestine, whereas atrogin-1 expression is largely restricted to striate muscle. FBXO25 was shown here to contain a functional F-box domain that binds to Skp1 and thereby to Roc1 and Cul1, the major components of SCF-type E3s. In addition, the productive SCF complex containing FBXO25 showed ubiquitin ligase activity. We investigated the differential expression of atrogin-1 and FBXO25 in fasted and dexamethasone-treated mice and also in rats with streptozotocin-induced diabetes. Although the atrogin-1 was strongly induced in muscle in all three models, no changes were observed in the expression of FBXO25. Therefore, here we have shown that FBXO25 is a novel F-box protein analogous to atrogin-1, which is not involved in muscle atrophy. Further functional studies should elucidate the exact role of FBXO25 in the ubiquitin-proteasome pathway. |