Quote reference 1):
"Levels of Atrogin 1 mRNA were significantly elevated in muscle biopsies of patients with ME/CFS compared with HCs (Healthy Controls) suggesting an increase in protein degradation processes in muscles of patients with ME/CFS compared with HCs. Atrogin-1 binds to polyubiquitinated proteins to direct them for subsequent degradation by the 26S proteasome and as such is an important regulator of ubiquitin-mediated protein degradation in skeletal muscle (69). Increased levels of Atrogin-1 mRNA are associated with reduced muscle mass (69) and in this study Atrogin-1 was associated with a significant reduction in muscle fibre size, although a detailed examination of muscle protein degradation was not undertaken."
Increased degradation of myosin light chain proteins may lead to increased plasma N,N,N-trimethyl-L-alanyl-L-proline betaine (TMAP) (3).
Atrogin 1, also known as muscle atrophy F-box (MAFbx), is encoded by FBXO32. Atrogin 1 degrades various muscle proteins, such as titin, nebulin, troponin, myosin-binding protein C, myosin light chains 1 and 2 and myosin heavy chains (2).
Read the blogpost:
Increased plasma N,N,N-trimethyl-L-alanyl-L-proline betaine in ME patients
preprint: 1) Arief Gusnanto, Kate Elizabeth Earl, George K Sakellariou, Daniel J Owens, Adam Lightfoot, Sandra A Fawcett, Euan Owen, Caroline A Staunton, Tu Shu, Fiona C Croden, Manuel Fenech, Melanie A Sinclair, Libuse Ratcliffe, Kasia A Whysall, Rebecca I Haynes, Nicola M Wells, Malcolm J Jackson, Graeme L Close, Clare L Lawton, Michael BJ Beadsworth, Louise Dye, Anne MCARDLE:
Discriminatory cytokine profiles predict muscle function, fatigue and cognitive function in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)
2) Steinbacher and Eckl: Impact of oxidative stress on exercising skeletal muscle. Biomolecules 2015 Apr 10;5(2):356-77.
3) Velenosi, T.J., Thomson, B.K.A., Tonial, N.C. et al. Untargeted metabolomics reveals N, N, N-trimethyl-L-alanyl-L-proline betaine (TMAP) as a novel biomarker of kidney function. Sci Rep 9, 6831 (2019). https://www.nature.com/articles/s41598-019-42992-3
https://doi.org/10.1038/s41598-019-42992-3 PMID: 31048706 PMCID: PMC6497643