Regulation of mTOR in chicken skeletal muscle by nutritional and physiological conditions

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06369
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 42010:Animal production science-related
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Nakashima Kazuki 国立研究開発法人農業・食品産業技術総合研究機構, 畜産研究部門, 上級研究員 (70370583)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: mTORC1 / mTORC2 / 骨格筋 / 鶏 / アミノ酸

Outline of Final Research Achievements

The mTOR is a central regulator of protein metabolism in cells. mTOR kinase assembles into two distinct complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) which differ in their composition, substrates, functions. Skeletal muscle mass is maintained by the balance between the rate of protein synthesis and protein degradation. Protein synthesis in skeletal muscle is crucially controlled by mTOR signaling However, in chicken skeletal muscles, the regulation of mTOR signaling by hormones, growth factors and nutrients remains unclear. Here, we showed that mTORC1 was stimulated by insulin, IGF-I, amino acids and chlorogenic acid, on the other hand, mTORC2 is stimulated by insulin and IGF-I but not the other nutrients in chick skeletal muscle cultures. mTORC1 but not mTORC2 was also stimulates by arginine and lysine. These results indicates that mTORC1 and mTORC2 is differently regulated by hormones, growth factors and nutrients in chicken skeletal muscles.

Free Research Field

家畜栄養生化学

Academic Significance and Societal Importance of the Research Achievements

本研究は、鶏骨格筋においてmTORを栄養生理学的に制御し、骨格筋量の増加の可能性を検討することを目的とし、栄養生理学的手法で鶏骨格筋のmTORを活性化することは可能であり、特に、アミノ酸（アルギニン）でmTORならびにタンパク質代謝が制御されていることを明らかにした学術的意義は大きい。また、家畜飼養の観点から、飼料中タンパク質含量の改変によるmTORを介した鶏骨格筋タンパク質代謝の制御が可能であり、鶏肉生産の増加への貢献が見込まれることから社会的意義は大きいと考えられる。