[Frontiers in Bioscience 16, 1445-1460, January 1, 2011]
Regulation of protein synthesis by amino acids in muscle of neonates
Agus Suryawan, Teresa A. Davis
United States Department Of Agriculture/Agriculture Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030
Figure 1. Fractional rates of protein synthesis in longissimus dorsi (LD) muscle of 6- and 26-day-old pigs in response to euinsulinemic-euglycemic-euaminoacidemic conditions (C), euinsulinemic-euglycemic-hyperaminoacidemic clamps (AA), and hyperinsulinemic-euglycemic-euaminoacidemic clamps (INS) (panel A). Fractional rates of protein synthesis in LD muscle of 6-day-old pigs in response to individual infusion of the branched-chain amino acids, leucine (Leu), isoleucine (Iso) and valine (Val), in comparison with saline (sal)/control (panel B). Values are means ± SEM, means with different letters differ at P < 0.05.
Figure 2. Recent concepts of the insulin- and amino acid-induced activation of mTORC1.
Figure 3. The regulation of leucine transport by glutamine leading to the activation of mTORC1 and protein synthesis.
Figure 4. The molecular model of amino acid-induced activation of mTORC1 and protein synthesis by PAT2.
Figure 5. Fractional rates of protein synthesis (A), raptor-mTOR interaction (B), S6K1 phosphorylation (C) and 4E-BP1 phosphorylation in longissimus dorsi (LD) muscle of 7-day-old pigs after 60 min of infusion of saline (Sal), 400 μmol∙kg−1∙h−1 leucine (Leu), and leucine with rapamycin (Leu+Rap). Values are means ± SEM; means with different letters differ at P < 0.05.
Figure 6. The regulation of protein synthesis by amino acids and insulin.