Display Settings:

Format

Send to:

Choose Destination
    Proc Natl Acad Sci U S A. 2009 May 26;106(21):8483-8. Epub 2009 May 7.

    The tail binds to the head-neck domain, inhibiting ATPase activity of myosin VIIA.

    Source

    Department of Physiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.

    Abstract

    Myosin VIIA is an unconventional myosin, responsible for human Usher syndrome type 1B, which causes hearing and visual loss. Here, we studied the molecular mechanism of regulation of myosin VIIA, which is currently unknown. Although it was originally thought that myosin VIIA is a dimeric myosin, our electron microscopic (EM) observations revealed that full-length Drosophila myosin VIIA (DM7A) is a monomer. Interestingly, the tail domain markedly inhibits the actin-activated ATPase activity of tailless DM7A at low Ca(2+) but not high Ca(2+). By examining various deletion constructs, we found that deletion of the distal IQ domain, the C-terminal region of the tail, and the N-terminal region of the tail abolishes the tail-induced inhibition of ATPase activity. Single-particle EM analysis of full-length DM7A at low Ca(2+) suggests that the tail folds back on to the head, where it contacts both the motor core domain and the neck domain, forming an inhibited conformation. We concluded that unconventional myosin that may be present a monomer in the cell can be regulated by intramolecular interaction of the tail with the head.

    PMID:
    19423668
    [PubMed - indexed for MEDLINE]
    PMCID:
    PMC2688991
    Free PMC Article

    Images from this publication.See all images (6) Free text

    Fig. 1.
    Fig. 3.
    Fig. 5.
    Fig. 2.
    Fig. 4.
    Fig. 6.

      Supplemental Content

      Icon for HighWire Press Icon for PubMed Central

      Save items

      loading

      Recent activity

      Your browsing activity is empty.

      Activity recording is turned off.

      Turn recording back on

      See more...
      Write to the Help Desk