Re-examination of Dietary Amino Acid Sensing Reveals a GCN2-Independent Mechanism.
Bottom Line: Animals cannot synthesize nine essential amino acids (EAAs) and must therefore obtain them from food.In contrast to previous results, we find that mice cannot rapidly identify threonine- or leucine-deficient food in common feeding paradigms.These behaviors are independent of the proposed amino acid sensor GCN2, pointing to the existence of an undescribed mechanism for rapid sensing of dietary EAAs.
Affiliation: Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.Show MeSH
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Mentions: We first attempted to replicate the result that mice consume less threonine-deficient (T-def) or leucine-deficient (L-def) food than control food in the first 1–3 hr of feeding. Test diets were synthesized that lacked one or more amino acids (Table S1) and used in a behavioral assay that compared intake of the test diet and control diet on different days in a randomized order (Figure 1A). Importantly, the test and control diets used in this paradigm were both novel, which ensures that differences in food intake reflect true dietary preferences and not neophobia (Corey, 1978).
Affiliation: Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.