Signal ways and regulatory factors of the synthesis and breakdown of proteins in skeletal muscle
Maintaining a certain balance between the synthesis and breakdown of proteins in skeletal muscle is a prerequisite for the normal growth and health of animals. The aim of this work is to systematize modern concepts of signaling pathways and regulatory factors involved in coordinating the processes of protein synthesis and turnover in skeletal muscle tissue. Anabolic and catabolic stimuli are integrated via signaling in systems that control the synthesis and breakdown of structural proteins in skeletal muscle. During periods of intensive growth, muscle mass accumulation is stimulated by an increase in protein synthesis at the mRNA translation level, and the mRNA cell pool depends on the number of nuclei. Therefore, the intensive synthesis of proteins in growing animals is due to the high rate of nuclear accumulation, this process decreases with age, the number of nuclei per unit length of muscle fiber reaches a plateau level. Genetic factors, hormones, amino acids, phytoecdysteroids, rhodanins, β-adrenergic agonists, tomatidine, ursolic acid affect protein metabolism via signaling pathways, changing the effectiveness of muscle growth. Throughout life, in skeletal muscle operate a number of proteolytic systems, including autophagy, the lysosomal system, the ubiquitin-proteasome pathway, calcium-dependent calpains and the family of caspases. Several signaling networks direct and coordinate these processes, contributing to the maintenance of protein homeostasis. Consideration of these factors provides certain guidelines for developing recommendations on improving the efficiency of feed conversion and improving the quality of meat products.