National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
HL036153
米国
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
HL124091
米国
引用
ジャーナル: J Mol Cell Cardiol / 年: 2026 タイトル: Pseudo-acetylation of ACTC1 K326 and K328 promotes dysinhibition of reconstituted human cardiac thin filaments. 著者: Kripa Chitre / Olga E Karpicheva / Chloe J King / Michael J Rynkiewicz / Axel J Fenwick / John F Dawson / D Brian Foster / William Lehman / Anthony Cammarato / 要旨: Electrostatic interactions between actin residues K326 and K328 and tropomyosin bias tropomyosin to an F-actin location where it blocks myosin attachment. K326/328 acetylation neutralizes their ...Electrostatic interactions between actin residues K326 and K328 and tropomyosin bias tropomyosin to an F-actin location where it blocks myosin attachment. K326/328 acetylation neutralizes their charge, potentially disrupting thin filament-based contractile regulation. We verified acetylation of K326/328 on human cardiac actin (ACTC1) and generated recombinant K326/328Q, pseudo-acetylated ACTC1. Pseudo-acetylation reduced inhibition of myosin-driven motility of F-actin-tropomyosin and F-actin-tropomyosin-troponin at low Ca. Cryo-EM-based and computational modeling revealed that pseudo-acetylation did not alter tropomyosin positioning along F-actin but decreased local F-actin-tropomyosin interaction energy. Thus, by reducing the energetic demands required for myosin to displace tropomyosin, ACTC1 K326/328 acetylation may promote contractile activation.