As Extracellular Glutamine Levels Decline, Asparagine Becomes an Essential Amino Acid.

ABSTRACT: When mammalian cells are deprived of glutamine, exogenous asparagine rescues cell survival and growth. Here we report that this rescue results from use of asparagine in protein synthesis. All mammalian cell lines tested lacked cytosolic asparaginase activity and could not utilize asparagine to produce other amino acids or biosynthetic intermediates. Instead, most glutamine-deprived cell lines are capable of sufficient glutamine synthesis to maintain essential amino acid uptake and production of glutamine-dependent biosynthetic precursors, with the exception of asparagine. While experimental introduction of cytosolic asparaginase could enhance the synthesis of glutamine and increase tricarboxylic acid cycle anaplerosis and the synthesis of nucleotide precursors, cytosolic asparaginase suppr

SUBMITTER: Pavlova NN 

PROVIDER: S-EPMC5803449 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature