Elucidating the Role of Phosphorylated Regulatory Light Chain Proteins (RLC) during Heart Failure Progression

Abstract

published atomic force microscopy data showing that utrophin is much stiffer than data previously reported for dystrophin. Here we show that the cell expression system employed impacts both the post-translational modification and mechanical behavior of a utrophin construct encoding the N-terminal actin binding domain through spectrin repeat 3 (UtrN-R3). UtrN-R3 expressed in insect cells showed significantly higher unfolding forces than when expressed in bacteria. Other analyses showed phosphorylation of UtrN-R3 from insect cell but not bacterial UtrN-R3. Our results demonstrate that the mechanical properties of utrophin are affected by the cell expression system employed and phosphorylation status. Our experiments also suggest a potential mechanism by which the mechanical stiffness of utrophin (and possibly dystrophin) can be regulated in vivo.