Fig. 5. Nuclear shuttling of NFATc1 and epigenetic histone H3 modifications upon acute exercise. (A) Confirmation of nuclear and sarcoplasmic fractions in skeletal muscles. We performed western blot for a nuclear marker protein (total H3) and a sarcoplasmic marker protein (GAPDH), and whole lysate, sarcoplasmic fraction, and nuclear fractions were loaded. Total H3 predominantly shows a signal in nuclear fractions, whereas GAPDH was predominantly detected in sarcoplasmic fractions. (B) NFATc1 was detected in sarcoplasmic and nuclear fractions of CON, 1xLevel, and 1xDh LAT and GAS muscles. As shown, NFATc1 abundances increased in nuclear fractions of 1xLevel and 1xDownhill compared to CON, whereas the sarcoplasmic fractions remained unchanged. The western blot shows results from LAT muscles, but is representative for GAS muscles (not shown). (C) The epigenetic histone H3 marks H3K9ac, H3K14ac, H3K27ac, and pH3Ser¹⁰ were analyzed in nuclear fractions of LAT (upper panel) and GAS (lower panel) muscles. As shown, H3 acetylations increase with both 1xLevel and 1xDownhill, whereas pH3Ser¹⁰ remains unchanged. n(western blot experiments) = 8 for each tested condition.