PQM-1 controls hypoxic survival via regulation of lipid metabolism

Animals have evolved responses to low oxygen conditions to ensure their survival. Here we have identified the C. elegans zinc finger transcription factor PQM-1 as a regulator of the hypoxic stress response. PQM-1 is required for the longevity of insulin signaling mutants, but surprisingly, loss of PQM-1 increases survival under hypoxic conditions. PQM-1 functions as a metabolic regulator by controlling oxygen consumption rates, suppressing hypoxic glycogen levels, and inhibiting the expression of the sorbitol dehydrogenase-1 SODH-1, a crucial enzyme for sugar metabolism. PQM-1 promotes intestinal fat metabolism by activating the expression of the stearoyl-CoA desaturase FAT-7, an oxygen consuming, rate-limiting enzyme in fatty acid biosynthesis. PQM-1 activity enhances fat accumulation in embryos under hypoxic conditions, thereby increasing survival rates of arrested progeny during hypoxia. Thus, while pqm-1 mutants increase survival of mothers, ultimately this loss is detrimental to progeny survival. Our data support a model in which PQM-1 controls a trade-off between lipid metabolic activity in the mother and her progeny to promote the survival of the species under hypoxic conditions.