Lysine acetylation of F-actin decreases tropomyosin-based inhibition of actomyosin activity.

ABSTRACT: Recent proteomics studies of vertebrate striated muscle have identified lysine acetylation at several sites on actin. Acetylation is a reversible post-translational modification that neutralizes lysine's positive charge. Positively charged residues on actin, particularly Lys³²⁶ and Lys³²⁸, are predicted to form critical electrostatic interactions with tropomyosin (Tpm) that promote its binding to filamentous (F)-actin and bias Tpm to an azimuthal location where it impedes myosin attachment. The troponin (Tn) complex also influences Tpm's position along F-actin as a function of Ca²⁺ to regulate exposure of myosin-binding sites and, thus, myosin cross-bridge recruitment and force production. Interestingly, Lys³²⁶ and Lys³²⁸ are among the

SUBMITTER: Schmidt W 

PROVIDER: S-EPMC7667958 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature