Reduced ATP turnover during hibernation in relaxed skeletal muscleDe Napoli, Cosimo (Avtor) Schmidt, Luisa (Avtor) Montesel, Mauro (Avtor) Cussonneau, Laura (Avtor) Sanniti, Samuele (Avtor) Marcucci, Lorenzo (Avtor) Germinario, Elena (Avtor) Kindberg, Jonas (Avtor) Evans, Alina L. (Avtor) Narici, Marco Vincenzo (Avtor) translational researchanimal physiologymetabolismHibernating brown bears, due to a drastic reduction in metabolic rate, show only moderate muscle wasting. Here, we evaluate if ATPase activity of resting skeletal muscle myosin can contribute to this energy sparing. By analyzing single muscle fibers taken from the samebears,eitherduring hibernationorin summer,wefindthatfibersfromhibernatingbearshaveamilddeclineinforce production and a significant reduction in ATPase activity. Single fiber proteomics, western blotting, and immunohistochemical analyses reveal major remodeling of the mitochondrial proteome during hibernation. Furthermore, using bioinformatical approaches and western blotting we find that phosphorylated myosin light chain, a known stimulator of basal myosin ATPase activity, is decreased in hibernating and disused muscles. These results suggestthatskeletalmusclelimitsenergylossbyreducingmyosinATPaseactivity, indicating a possible role for myosin ATPase activity modulation in multiple muscle wasting conditions.20252026-01-14 12:23:17Neznano25252sl©The Author(s)