Cell-non-autonomous effects of signaling in the nervous system of animals can influence diverse aspects of organismal physiology. We previously showed that phosphorylation of Ser49 of eIF2α in two chemosensory neurons by PEK-1/PERK promotes entry of Caenorhabditis elegans into dauer diapause. Here, we identified and characterized the molecular determinants that confer sensitivity to effects of neuronal eIF2α phosphorylation on development and physiology of C. elegans. Isolation and characterization of mutations in eif-2B.1 encoding the alpha subunit of eIF2B support a conserved role previously established by studies in yeast for eIF2α in providing a binding site for phosphorylated eIF2α to inhibit the exchange factor eIF2B catalytic activity that is required for translation initiation. We also identified a mutation in eif-2.3, encoding the gamma subunit of eIF2, which confers insensitivity to the effects of phosphorylated eIF2α while also altering the requirement for eIF2Bγ. In addition, we show that constitutive expression of eIF2α carrying a phosphomimetic S49D mutation in the ASI pair of sensory neurons confers dramatic effects on growth, metabolism and reproduction in adult transgenic animals, phenocopying systemic responses to starvation. Furthermore, we show that constitutive expression of eIF2α carrying a phosphomimetic S49D mutation in the ASI neurons enhances dauer entry through bypassing the requirement for nutritionally deficient conditions. Our data suggest that the state of eIF2α phosphorylation in the ASI sensory neuron pair may modulate internal nutrient sensing and signaling pathways, with corresponding organismal effects on development and metabolism.
- Received January 25, 2017.
- Accepted March 9, 2017.
- Copyright © 2017, The Genetics Society of America