title: Deficiency of Myo18B in mice results in embryonic lethality with cardiac myofibrillar aberrations.
abstract: Myo18B is an unconventional myosin family protein expressed predominantly in muscle cells. Although conventional myosins are known to be localized on the A-bands and function as a molecular motor for muscle contraction, Myo18B protein was localized on the Z-lines of myofibrils in striated muscles. Like Myo18A, another 18th class of myosin, the N-terminal unique domain of the protein and not the motor domain and the coiled-coil tail is critical for its localization to F-actin in myocytes. Myo18B expression was induced by myogenic differentiation through the binding of myocyte-specific enhancer factor-2 to its promoter. Deficiency of Myo18B caused an embryonic lethality in mice accompanied by disruption of myofibrillar structures in cardiac myocytes at embryonic day 10.5. Thus, Myo18B is a unique unconventional myosin that is predominantly expressed in myocytes and whose expression is essential for the development and/or maintenance of myofibrillar structure.
authors.affiliation: Biology Division, National Cancer Center Research Institute, Tokyo 104-0045, Japan.
authors.forename: Rieko
authors.initials: R
authors.lastname: Ajima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Akazawa
authors.forename: Maho
authors.initials: M
authors.lastname: Kodama
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Takeshita
authors.forename: Ayaka
authors.initials: A
authors.lastname: Otsuka
authors.forename: Takashi
authors.initials: T
authors.lastname: Kohno
authors.forename: Issei
authors.initials: I
authors.lastname: Komuro
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ochiya
authors.forename: Jun
authors.initials: J
authors.lastname: Yokota