Optogenetic induction of mechanical muscle stress identifies myosin regulatory ubiquitin ligase NHL-1 in C. elegans

• Published in: Nature communications Vol. 15; no. 1; pp. 6879 - 18
• Main Authors: Kutzner, Carl Elias, Bauer, Karen Carolyn, Lackmann, Jan-Wilm, Acton, Richard James, Sarkar, Anwesha, Pokrzywa, Wojciech, Hoppe, Thorsten
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.08.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 13; 13/1; 13/44; 13/89; 14/19; 14/28; 38; 38/111; 38/77; 38/91; 42; 631/1647/2253; 631/45/470/1981; 631/80/474/2073; 631/80/474/2085; 64/11; 82/58; Animals; Animals, Genetically Modified; Caenorhabditis elegans - genetics; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; Epistasis; Humanities and Social Sciences; Immunoprecipitation; Mass spectrometry; Mass spectroscopy; Mechanical properties; Molecular Chaperones; multidisciplinary; Muscle contraction; Muscle Contraction - physiology; Muscles; Muscles - metabolism; Muscular function; Myosin; Myosins - genetics; Myosins - metabolism; Optogenetics; Proteomes; Proteostasis; Science; Science (multidisciplinary); Stress; Stress, Mechanical; Ubiquitin-protein ligase; Ubiquitin-Protein Ligases - genetics; Ubiquitin-Protein Ligases - metabolism; Ubiquitination
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-51069-3

Mechanical stress during muscle contraction is a constant threat to proteome integrity. However, there is a lack of experimental systems to identify critical proteostasis regulators under mechanical stress conditions. Here, we present the transgenic Caenorhabditis elegans model OptIMMuS (Optogenetic Induction of Mechanical Muscle Stress) to study changes in the proteostasis network associated with mechanical forces. Repeated blue light exposure of a muscle-expressed Chlamydomonas rheinhardii channelrhodopsin-2 variant results in sustained muscle contraction and mechanical stress. Using OptIMMuS, combined with proximity labeling and mass spectrometry, we identify regulators that cooperate with the myosin-directed chaperone UNC-45 in muscle proteostasis. One of these is the TRIM E3 ligase NHL-1, which interacts with UNC-45 and muscle myosin in genetic epistasis and co-immunoprecipitation experiments. We provide evidence that the ubiquitylation activity of NHL-1 regulates myosin levels and functionality under mechanical stress. In the future, OptIMMuS will help to identify muscle-specific proteostasis regulators of therapeutic relevance. Mechanical stress during muscle contraction constantly threatens the proteome. Here, Kutzner et al . present the OptIMMuS model and identify the TRIM E3 ligase NHL-1 to regulate myosin levels and function upon mechanical stress.