Myosin-13

Myosin-13 (MYH13) is a fast-twitch myosin that mediates high-velocity, low-tension contractions in specific striated muscles (UniProt: Q9UKX3). The protein functions as a molecular motor in muscle tissue, where it generates force through ATP-dependent interactions with actin filaments. At 223.6 kDa, it is one of the larger members of the myosin family.

Myosin-13 is primarily expressed in skeletal muscle tissues involved in rapid contractile activity. No disease associations are documented in UniProt for this protein. Its expression is generally restricted to specialized muscle fibers, with limited presence in other tissues.

In Alzheimer's Disease, Myosin-13 shows reduced abundance in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). The protein was downregulated with a mean log2 fold-change of −0.31 across one subcellular fraction in TMT-labeled proteomics analysis of human brain samples. This modest decrease may reflect alterations in muscular or cytoskeletal dynamics associated with AD pathology, though the functional significance of reduced myosin-13 in brain tissue remains to be determined.