Cytoskeletal remodeling slows cross-bridge cycling and ATP hydrolysis rates in airway smooth muscle.

ABSTRACT: During isometric activation of airway smooth muscle (ASM), cross-bridge cycling and ATP hydrolysis rates decline across time even though isometric force is sustained. Thus, tension cost (i.e., ATP hydrolysis rate per unit of force during activation) decreases with time. The "latch-state" hypothesis attributes the dynamic change in cross-bridge cycling and ATP hydrolysis rates to changes in phosphorylation of the regulatory myosin light chain (rMLC₂₀ ). However, we previously showed that in ASM, the extent of rMLC₂₀ phosphorylation remains unchanged during sustained isometric force. As an alternative, we hypothesized that cytoskeletal remodeling within ASM cells results in increased internal loading of contractile proteins that slows cross-bridge cycling and ATP hydrol

SUBMITTER: Delmotte P 

PROVIDER: S-EPMC7435030 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature