Myosin-11

Myosin-11 (MYH11) is a thick filament protein that functions in muscle contraction, particularly in smooth muscle tissues (UniProt: P35749). It is a large coiled-coil protein involved in force generation across contractile systems. Mutations in MYH11 are associated with several inherited disorders affecting smooth muscle function, including familial thoracic aortic aneurysm (AAT4), megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS2), and visceral myopathy (VSCM2), which collectively underscore its critical role in vascular and visceral muscle homeostasis.

In the context of Alzheimer's Disease, MYH11 is significantly upregulated in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). Quantitative proteomic analysis detected a mean log2 fold-change of +1.34 in the TMT-labeled human brain sample, measured across subcellular fractions using data-dependent acquisition mass spectrometry. This upregulation suggests potential involvement of contractile protein remodeling or smooth muscle dysfunction in the pathological cascade of neurodegeneration, though the mechanistic significance remains to be elucidated.