Location: Children's Nutrition Research CenterTitle: Differential expression of proton-assisted amino acid transporters (PAT and PAT) in tissues of neonatal pigs Author
Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/21/2011
Publication Date: 3/17/2011
Citation: Suryawan, A., Nguyen, H.V., Almonaci, R.D., Davis, T. 2011. Differential expression of proton-assisted amino acid transporters (PAT and PAT) in tissues of neonatal pigs [abstract]. In: Proceedings of the Federation of American Societies for Experimental Biology Conference, Session: Nutrient-gene interactions, April 07-13, 2011, Washington, D.C. 25:782.10. Interpretive Summary:
Technical Abstract: The PATs have been identified as growth-regulatory nutrient sensors in Drosophila and as activators of mammalian target of rapamycin (mTOR) in mammalian cell cultures. These studies suggest that, beyond their classical function as transporters of simple amino acids (AA), the PATs act as tranceptors, i.e., signaling components that participate in the mTOR activation. However, the role of the PATs in regulating growth in mammalian species in vivo is unknown. This study aimed to determine whether insulin or AA alter PAT1 and PAT2 abundance and PAT2-mTOR complex formation and whether the responses change with age. Overnight fasted 6- and 26-d-old pigs were infused for 2 h with saline, insulin, or AA to achieve fed levels. PAT1 abundance was higher (P<0.05) in skeletal muscle, liver, jejunum, and kidney, but not heart, of 6- compared to 26-d-old pigs. PAT2 abundance in skeletal muscle, liver, jejunum, and heart, but not kidney, was higher (P<0.05) in 6- than in 26-d-old pigs. The PAT2-mTOR association in skeletal muscle decreased with development in parallel with the developmental decline in mTOR activation. Neither insulin nor AA altered PAT2-mTOR association. Since the abundance of the AA transporters is considered to reflect their activity, we conclude that the high abundance of the PATs in neonatal tissues may contribute to the high growth rate of neonates.