Premium
Rapamycin‐Regulated Ubiquitin Specific Peptidases Expression in Cardiocytes
Author(s) -
Zanetti Arthus Vilar Deolindo,
Santos Lucas Carvalho,
Schoeps Vinicius Andreoli,
Sanzovo Paula Sajovic,
Carniello Jose Victor Scarpa,
Manso Andre Augusto Simoes,
Sellke Frank William,
Bianchi Cesario
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.1089.4
Subject(s) - ubiquitin , pi3k/akt/mtor pathway , proteasome , autophagy , protein degradation , biology , proteasome inhibitor , microbiology and biotechnology , in vivo , signal transduction , biochemistry , apoptosis , gene , genetics
The mechanistic target of rapamycin (mTOR) regulates protein degradation through autophagic/lysosomal activity. However, the mTOR effects on protein degradation by the ubiquitin/proteasome pathway have not been established. Protein ubiquitination is regulated by a balance of polyubiquitin ligases and ubiquitin specific peptidases (USP). OBJECTIVE To determine whether mTOR inhibition could modify the ubiquitin/proteasome pathway. METHODS Pigs were treated with placebo or 4mg/daily rapamycin (RAPA; mTOR inhibitor) for 1 week (n=5/group). H9C2 (cardiomyocytes) cells were cultured in DMEM and treated with 600 nM RAPA for up to 3 days. RNA and protein levels were quantified by q_PCR and western blotting and statistically analyzed (ANOVA / t‐Test). RESULTS RAPA treatments inhibited mTOR [lower p‐P70S6K(T389)] both in vivo and in vitro. In vivo RAPA decreased protein levels of USP11 and 28 and in vitro RAPA decreased mRNA levels of USP11, 24, 28 and 39 and proteins levels of USP28 and 39 that were associated with increased total protein ubiquitination. CONCLUSION These results document the regulation of the ubiquitin/proteasome pathway by mTOR and reveals that mTOR activity may regulate cellular protein levels through degradation by both lysosomal and proteasomal pathways. Further studies will address the importance of RAPA‐regulated USP11, USP28, and USP39 levels in cardiac cells.