Serine/threonine-protein kinase which responds to activation by environmental stress by phosphorylating a number of transcription factors such as daf-16, and thus regulates transcriptional activity. By phosphorylating daf-16, plays a role in daf-16 nuclear translocation in intestinal cells in response to environmental stresses such as heat and oxidative stresses (PubMed:17894411). Downstream of jkk-1, may coordinate locomotion via type-D GABAergic motoneurons and regulates synaptic vesicle transport in conjunction with unc-16. Independently of jkk-1, may regulate some mechanosensory responses, such as response to touch (PubMed:11566876). Independently of jkk-1 and downstream of mek-1, plays a role in resistance to heavy metals, such as Cu(2+) or Cd(2+) (PubMed:11566876). Regulates germline cell apoptosis in response to heavy metals such as Cu(2+) and arsenite (PubMed:18597494, PubMed:19497412). Required for dopaminergic CEP neuron degeneration in response to Mn(2+) (PubMed:23721876). Required for normal sleep bout quantity and arousal thresholds during the transition from the last larval stage to adulthood in well-fed animals (PubMed:29523076). Downstream of jkk-1 but independently of mek-1, positively regulates lifespan (PubMed:15767565). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Activated by threonine and tyrosine phosphorylation by either of the dual specificity kinases, jkk-1 and mek-1. Binds to the scaffolding protein, unc-16. Unc-16 also binds other components of the JNK signaling pathway (PubMed:11738026). Interacts with daf-16 (PubMed:15767565). Expressed in most neurons, including nerve ring, head ganglions, dorsal and ventral nerve cords and tail ganglions (PubMed:10393177). The Thr-276/Tyr-278 phosphorylated form is present in the nerve ring upon heat exposure (PubMed:17894411). Isoform a and isoform b are expressed in embryo and in all larval stages. The TXY motif contains the threonine and tyrosine residues whose phosphorylation activates the MAP kinases. Dually phosphorylated on Thr-276 and Tyr-278, which activates the enzyme. RNAi-mediated knockdown prevents Mn(2+)-induced dopaminergic CEP neuron degeneration (PubMed:23721876). RNAi-mediated knockdown targeted to neurons results in increased total time in sleep bouts (PubMed:29523076). Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily.