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: In a choice assay controlling for dietary novelty (Figure 3A), wild-type mice had no preference for control over T-def chow (Figure 3B). When given a choice between control and doubly deficient TL-def chow, mice again had no preference for control and in fact consumed more TL-def food (Figure 3C). However, mice did show a strong preference for control over AA-def food, consuming in most cases an undetectable amount of AA-def food in 3 hr (0.47 ± 0.07 g versus 0 ± 0 g) and overnight (3.4 ± 0.1 g versus 0.03 ± 0.03 g; Figure 3D). Thus, this choice assay can robustly detect preference between two diets, but mice do not identify and reject T-def or L-def diets on a timescale of up to 21 hr when given a choice.
Affiliation: Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.