Thick filament mechano-sensing is a calcium-independent regulatory mechanism in skeletal muscle

Recent X-ray diffraction studies on actively contracting fibres from skeletal muscle showed that the number of myosin motors available to interact with actin-containing thin filaments is controlled by the stress in the myosin-containing thick filaments. Those results suggested that thick filament me...

Full description

Saved in:

Bibliographic Details
Published in:	Nature communications 2016-10, Vol.7 (1), p.13281-13281, Article 13281
Main Authors:	Fusi, L, Brunello, E, Yan, Z, Irving, M
Format:	Article
Language:	eng
Subjects:	Animals Calcium - physiology Calcium Signaling Kinetics Male Muscle, Skeletal - physiology Musculoskeletal system Myosins - physiology Phosphorylation Physiology Pressure Psoas Muscles - physiology Rabbits Sarcomeres - physiology Signal Transduction Time Factors X-Ray Diffraction
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Recent X-ray diffraction studies on actively contracting fibres from skeletal muscle showed that the number of myosin motors available to interact with actin-containing thin filaments is controlled by the stress in the myosin-containing thick filaments. Those results suggested that thick filament mechano-sensing might constitute a novel regulatory mechanism in striated muscles that acts independently of the well-known thin filament-mediated calcium signalling pathway. Here we test that hypothesis using probes attached to the myosin regulatory light chain in demembranated muscle fibres. We show that both the extent and kinetics of thick filament activation depend on thick filament stress but are independent of intracellular calcium concentration in the physiological range. These results establish direct control of myosin motors by thick filament mechano-sensing as a general regulatory mechanism in skeletal muscle that is independent of the canonical calcium signalling pathway.
ISSN:	2041-1723 2041-1723