Reduced passive force in skeletal muscles lacking protein arginylation.
Arginylation is a posttranslational modification that plays a global role in mammals. Mice lacking the enzyme arginyltransferase in skeletal muscles exhibit reduced contractile forces that have been linked to a reduction in myosin cross-bridge formation. The role of arginylation in passive skeletal myofibril forces has never been investigated. In this study, we used single sarcomere and myofibril measurements and observed that lack of arginylation leads to a pronounced reduction in passive forces in skeletal muscles. Mass spectrometry indicated that skeletal muscle titin, the protein primarily linked to passive force generation, is arginylated on five sites located within the A band, an important area for protein-protein interactions. We propose a mechanism for passive force regulation by arginylation through modulation of protein-protein binding between the titin molecule and the thick filament. Key points are as follows: 1) active and passive forces were decreased in myofibrils and single sarcomeres isolated from muscles lacking arginyl-tRNA-protein transferase (ATE1). 2) Mass spectrometry revealed five sites for arginylation within titin molecules. All sites are located within the A-band portion of titin, an important region for protein-protein interactions. 3) Our data suggest that arginylation of titin is required for proper passive force development in skeletal muscles.
Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada;
Felipe S
http://orcid.org/0000-0003-2493-8872
FS
Leite
Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada;
Fábio C
FC
Minozzo
Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada;
Albert
A
Kalganov
Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada;
Anabelle S
AS
Cornachione
Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada;
Yu-Shu
YS
Cheng
Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;
Nicolae A
NA
Leu
The Scripps Research Institute, Department of Chemical Physiology, La Jolla, California;
Xuemei
X
Han
Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona; and.
Chandra
C
Saripalli
The Scripps Research Institute, Department of Chemical Physiology, La Jolla, California;
John R
JR
Yates
Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona; and.
Henk
H
Granzier
Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;
Anna S
AS
Kashina
Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada; Departments of Physics and Physiology, McGill University, Montreal, Quebec, Canada dilson.rassier@mcgill.ca.
Dilson E
DE
Rassier
D019881:Aminoacyltransferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D064211:Connectin / Q000737:chemistry* / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D009124:Muscle Proteins / Q000737:chemistry / Q000502:physiology; D009210:Myofibrils / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D013314:Stress, Mechanical; D013329:Structure-Activity Relationship
D064211:Connectin; D009124:Muscle Proteins; D019881:Aminoacyltransferases; C019727:arginyltransferase
arginylation; myofibril; passive force; posttranslational modification; sarcomere; titin