Phosphatase regulatory subunit MYPT2 knockout partially compensates for the cardiac dysfunction in mice caused by lack of myosin light chain kinase 3

Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved..

Cardiac contraction is modulated by the phosphorylation state of myosin regulatory light chain 2 (MLC-2v). The level of MLC-2v phosphorylation is dependent on the opposing activities of MLC kinases and phosphatases. The predominant MLC phosphatase found in cardiac myocytes contains Myosin Phosphatase Targeting Subunit 2 (MYPT2). Overexpression of MYPT2 in cardiac myocytes results in a decreased level of MLC phosphorylation, reduced left ventricular contraction, and induction of hypertrophy; however, the effect of knocking out MYPT2 on cardiac function is unknown. We obtained heterozygous mice containing a MYPT2 null allele from the Mutant Mouse Resource Center. These mice were produced in a C57BL/6N background which lack MLCK3, the main regulatory light chain kinase in cardiac myocytes. We found that mice null for MYPT2 were viable and had no obvious phenotypic abnormality when compared to WT mice. Additionally, we determined that WT C57BL/6N mice had a low basal level of MLC-2v phosphorylation, which was significantly increased when MYPT2 was absent. At 12-weeks, MYPT2 KO mice had smaller hearts and showed downregulation of genes involved in cardiac remodeling. Using cardiac echo, we found that 24-week-old male MYPT2 KO mice had decreased heart size with increased fractional shortening compared to their MYPT2 WT littermates. Collectively, these studies highlight the important role that MYPT2 plays in cardiac function in vivo and demonstrate that its deletion can partially compensate for the lack of MLCK3.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:299

Enthalten in:

The Journal of biological chemistry - 299(2023), 4 vom: 25. Apr., Seite 104584

Sprache:

Englisch

Beteiligte Personen:

Hu, Tingfei [VerfasserIn]
Kalyanaraman, Hema [VerfasserIn]
Pilz, Renate B [VerfasserIn]
Casteel, Darren E [VerfasserIn]

Links:

Volltext

Themen:

Cardiac function
EC 2.7.11.18
EC 3.1.3.16
EC 3.1.3.53
Journal Article
MLC-2v
MLCK3
MYPT2
Myosin Light Chains
Myosin-Light-Chain Kinase
Myosin-Light-Chain Phosphatase
PP1Cδ
Phosphoprotein Phosphatases
Research Support, N.I.H., Extramural

Anmerkungen:

Date Completed 28.04.2023

Date Revised 10.05.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jbc.2023.104584

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM353953121