Glutamine transport into cells

Novogrodosky, A., Nehring, RE., Jr and Meister, A. (1979). Inhibition of amine acid transport into lymphoid cells by the glutamine analog L-2-amino-4-oxo-5-chloropentanoate. Proc. Natl Acad. Sci. USA 76, 4932-4935. 

Glutamine is transported into the cytosol of the cell by means of two kinds of transporters Na+-dependent and Na+-independent. Once in the cytosol, glutamine must be transported into the mitochondria, where it is metabolized. 

The amino acid substrates that are most recognized by Y-glulamyltranspeplidase are cysteine, glutamine, methioniney alanine, and serine. The products of the reaction, apparently, are efficiently transported into the epithelial cell, and then broken down into their constituent amino acids in the cell. The elucidation of the series of reactions involving formation of the y-glutamyl-amino acid, absorption of the products, hydrolysis of the products, and ro-formation of glutathione was mainly the work of Alton Meister (Meister, 1989). 

Some of the amino acids undergo facilitated diffusion through selective transport proteins into the bloodstream, from which they are taken up by the liver and other organs. Others, particularly glutamate, glutamine, aspartate, and asparagine, are metabolized by the gut cells for energy. 

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