Energy intake modulates intramuscular mTORC1 signaling and ubiquitin‐mediated proteolysis during energy deficit independent of dietary protein variations
Abstract
Effects of variations in habitual and acute dietary protein consumption on intracellular regulators of human skeletal muscle mass during energy deficit (ED) were investigated. Using a randomized‐block design, 32 men and 7 women consumed diets providing protein at 0.8, 1.6, or 2.4 g·kg−1·d−1 for 31 days. A 10‐day weight maintenance (WM) period preceded 21 days of ED, during which energy intake was reduced to 60% of daily requirements. Phosphorylation of mTORC1 associated signaling proteins, protein ubiquitylation (Ub), and NFκB expression were assessed in vastus lateralis muscle samples obtained after an overnight fast (FAST) and again 120 min after consuming a mixed meal (480 kcal, 20 g protein; FED) on days 10 and 31. Independent of dietary protein level and feeding state, Ub was 25% higher (PS6K1 phosphorylation, as FED‐ED levels were 26% lower than FED‐WM (energy‐by‐feeding, PPPS6K1 sensitivity to feeding, although energy consumption, independent of habitual protein intake, may confer skeletal muscle protection through concomitant stimulation of mTORC1 signaling and inhibition of Ub during ED.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 01, 2013
- Source ID
- 10.1096/fasebj.27.1_supplement.631.1
Entities
People
- Andrew J Young
- James P. Mcclung
- Jay J. Cao
- John Walter Carbone
- Lee M. Margolis
- Stefan M. Pasiakos
Organizations
- Agricultural Research Service
- Eastern Michigan University
- United States Army Medical Research and Development Command
- United States Army Research Institute of Environmental Medicine