RT Journal Article SR Electronic T1 Regulation of axonal morphogenesis by the mitochondrial protein Efhd1 JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202000753 DO 10.26508/lsa.202000753 VO 3 IS 7 A1 Ulisse, Valeria A1 Dey, Swagata A1 Rothbard, Deborah E A1 Zeevi, Einav A1 Gokhman, Irena A1 Dadosh, Tali A1 Minis, Adi A1 Yaron, Avraham YR 2020 UL http://www.life-science-alliance.org/content/3/7/e202000753.abstract AB During development, neurons adjust their energy balance to meet the high demands of robust axonal growth and branching. The mechanisms that regulate this tuning are largely unknown. Here, we show that sensory neurons lacking liver kinase B1 (Lkb1), a master regulator of energy homeostasis, exhibit impaired axonal growth and branching. Biochemical analysis of these neurons revealed reduction in axonal ATP levels, whereas transcriptome analysis uncovered down-regulation of Efhd1 (EF-hand domain family member D1), a mitochondrial Ca2+-binding protein. Genetic ablation of Efhd1 in mice resulted in reduced axonal morphogenesis as well as enhanced neuronal death. Strikingly, this ablation causes mitochondrial dysfunction and a decrease in axonal ATP levels. Moreover, Efhd1 KO sensory neurons display shortened mitochondria at the axonal growth cones, activation of the AMP-activated protein kinase (AMPK)–Ulk (Unc-51–like autophagy-activating kinase 1) pathway and an increase in autophagic flux. Overall, this work uncovers a new mitochondrial regulator that is required for axonal morphogenesis.