[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

FIGURES

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.