{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nMyo18B is an unconventional myosin protein that plays a pivotal role in the assembly and maintenance of myofibrillar structures in striated muscle. Distinct from conventional myosins whose motor domains direct localization to the A‐bands, Myo18B relies on its unique N‐terminal domain for localization to F‐actin at the Z‐lines. Its expression is upregulated during myogenic differentiation through the action of myocyte‐specific enhancer factor-2, and its absence leads to severe defects in myofibril organization, resulting in embryonic lethality in mice."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn addition to its structural role in muscle, Myo18B has been implicated as a tumor suppressor. Studies have shown that Myo18B interacts with the Homer/Ves1 family protein HOMER2, and together they localize to F‐actin-rich regions such as stress fibers and membrane protrusions. The cooperative interaction between MYO18B and HOMER2 enhances the suppression of anchorage-independent growth, suggesting a functional partnership that contributes to halting tumor progression."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nMoreover, in the context of skeletal muscle in rheumatoid arthritis, deregulation by a microRNA has emerged as a key mechanism modulating Myo18B function. Specifically, overexpression of a microRNA—reported in the literature as miR‑1760—results in the direct targeting and downregulation of Myo18B in C2C12 myoblasts. This downregulation leads to impaired cell proliferation, cell cycle progression, migration, and differentiation, highlighting a regulatory axis where aberrant microRNA activity negatively impacts muscle regeneration and development."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Rieko Ajima, Hiroshi Akazawa, Maho Kodama, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Deficiency of Myo18B in mice results in embryonic lethality with cardiac myofibrillar aberrations."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Genes Cells (2008)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1111/j.1365-2443.2008.01226.x"}], "href": "https://doi.org/10.1111/j.1365-2443.2008.01226.x"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "18761673"}], "href": "https://pubmed.ncbi.nlm.nih.gov/18761673"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Rieko Ajima, Keiko Kajiya, Takeshi Inoue, et al. "}, {"type": "b", "children": [{"type": "t", "text": "HOMER2 binds MYO18B and enhances its activity to suppress anchorage independent growth."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Biochem Biophys Res Commun (2007)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.bbrc.2007.03.060"}], "href": "https://doi.org/10.1016/j.bbrc.2007.03.060"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "17386922"}], "href": "https://pubmed.ncbi.nlm.nih.gov/17386922"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Xujun Tang, Jiuxia Wang, Shuhong Zhou, et al. "}, {"type": "b", "children": [{"type": "t", "text": "miR‑760 regulates skeletal muscle proliferation in rheumatoid arthritis by targeting Myo18b."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Med Rep (2019)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.3892/mmr.2019.10775"}], "href": "https://doi.org/10.3892/mmr.2019.10775"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "31661144"}], "href": "https://pubmed.ncbi.nlm.nih.gov/31661144"}]}]}]}