Fig 2: Representative Western blot results (A) and content of proteins FBP2 (B) and MCT1 (C) in the soleus, plantaris, and gastrocnemius muscles (Experiment 4). Data are expressed as means ?± ?SEM with n ?= ?7. **p ?< ?0.01 vs. soleus muscle. ††p < 0.01 vs. plantaris muscle.

Fig 3: Fbp2 deletion did not alter glucose metabolism during feeding-mimicking conditions.a Plasma glucose level, b glucose infusion rate during hyperinsulinemic-euglycemic clamp, c basal and clamped glucose level, d percentage of suppression of hepatic glucose output, and e clamped glucose uptake, glycolysis rate, and glycogen synthesis rate calculated using the hyperinsulinemic-euglycemic clamp results. n = 9 per group. f Muscle 2-DOG uptake results. n = 8–9 per group. HGP hepatic glucose production, Rd glucose disposal rate, GS glycogen synthesis rate. Data are expressed as the mean ± SEM and were analyzed by two-way ANOVA with post hoc analysis for a and b and by Student’s t-test for c–g. **P < 0.01, ***P < 0.001, ns nonsignificant.

Fig 4: Fbp2 was important for cold tolerance during fasting conditions.a Body temperature changes in WT and Fbp2 KO mice in cold stress experiments, n = 4 for the RT group; n = 8 for the cold group. b Glycogen content in the TA and QD muscles of WT and Fbp2 KO mice after cold stress experiments. n = 5 per group. c Glycogen content depending on cold exposure time (left) and glycogen content decrease after cold stress experiments (right) in the TA muscle of WT and Fbp2 KO mice. n = 5 per group. d Glycogen content in the QD muscle of WT and Fbp2 KO mice at room temperature. n = 5 per group. e Immunoblotting results of PKA substrate phosphorylation in WT and Fbp2 KO mice in cold stress experiments. n = 5 per group. f Gene expression analysis in the GAS muscle of WT and Fbp2 KO mice after cold stress. n = 4–6 per group. g Body temperature change, h body weight change, and i daily food intake of WT and Fbp2 KO mice in cold stress experiments for 3 weeks. n = 4–7 per group. h hour, TA tibialis anterior, QD quadriceps, PKA protein kinase A, Pygm glycogen phosphorylase, muscle associated, G6pi glucose-6-phosphate isomerase, Pfk1 phosphofructokinase 1, Pgm2 phosphoglucomutase 2, Gys1 glycogen synthase 1. Data are expressed as the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001 by Student’s t-test. ++P < 0.01, +++P < 0.001 by two-way ANOVA with post hoc analysis for a. ns nonsignificant.

Fig 5: Fbp2 was abundant in white skeletal muscle, and Fbp2 deletion changed energy metabolism.a Tissue-specific gene expression patterns of Fbp1 and Fbp2 in WT mice analyzed by quantitative reverse transcription polymerase chain reaction (RT-PCR). ND Nondetected. n = 4 per group. b Tissue-specific Fbp2 protein expression pattern in WT mice analyzed by immunoblotting. c Fbp2 gene expression in the soleus and extensor digitorum longus muscle of WT mice analyzed by quantitative RT-PCR. n = 3 per group. d Body composition analysis by the 1H-nuclear magnetic resonance system including body weight, fat mass, and lean mass. n = 8 per group. e Weight of various skeletal muscles. n = 6 per group. f Locomotor activity, h whole-body O2 consumption (VO2), and j whole-body CO2 production (VCO2) of WT and Fbp2 KO mice during the 72-h analysis. n = 8 per group. 24 h, day and night time averages of g locomotor activity, i VO2, k VCO2. GAS gastrocnemius, TA tibialis anterior, QD quadriceps, EDL extensor digitorum longus. Data are expressed as the mean ± SEM. *P < 0.05, **P < 0.01 by Student’s t-test for (c–e, g, i, k). ++P < 0.01, +++P < 0.001 by two-way analysis of variance (ANOVA) with post hoc analysis for (f) and #P < 0.05 by Student’s t-test at each time point for h and j. ns nonsignificant.