Functional Role of an Unusual Transmembrane Acidic Residue in the Calcium Pump Regulator Myoregulin.

ABSTRACT: Myoregulin (MLN) is a member of the regulin family, a group of homologous membrane proteins that bind to and regulate the activity of the sarcoplasmic reticulum Ca²⁺-ATPase (SERCA). MLN, which is expressed in skeletal muscle, contains an acidic residue in its transmembrane domain. The location of this residue, Asp35, is unusual because the relative occurrence of aspartate is very rare (<0.2%) within the transmembrane helix regions. Therefore, we used atomistic simulations and ATPase activity assays of protein co-reconstitutions to probe the functional role of MLN residue Asp35. These structural and functional studies showed Asp35 has no effects on SERCA's affinity for Ca²⁺ or the structural integrity of MLN in the lipid bilayer. Instead, Asp35 controls SERCA inhibitio

SUBMITTER: Liu AY 

PROVIDER: S-EPMC12278766 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature