Single-headed myosin II acts as a dominant negative mutation in Dictyostelium.

Journal Article (Journal Article)

Conventional myosin II is an essential protein for cytokinesis, capping of cell surface receptors, and development of Dictyostelium cells. Myosin II also plays an important role in the polarization and movement of cells. All conventional myosins are double-headed molecules but the significance of this structure is not understood since single-headed myosin II can produce movement and force in vitro. We found that expression of the tail portion of myosin II in Dictyostelium led to the formation of single-headed myosin II in vivo. The resultant cells contain an approximately equal ratio of double- and single-headed myosin II molecules. Surprisingly, these cells were completely blocked in cytokinesis and capping of concanavalin A receptors although development into fruiting bodies was not impaired. We found that this phenotype is not due to defects in myosin light chain phosphorylation. These results show that single-headed myosin II cannot function properly in vivo and that it acts as a dominant negative mutation for myosin II function. These results suggest the possibility that cooperativity of myosin II heads is critical for force production in vivo.

Full Text

Duke Authors

Cited Authors

  • Burns, CG; Larochelle, DA; Erickson, H; Reedy, M; De Lozanne, A

Published Date

  • August 29, 1995

Published In

Volume / Issue

  • 92 / 18

Start / End Page

  • 8244 - 8248

PubMed ID

  • 7667276

Pubmed Central ID

  • PMC41133

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.92.18.8244


  • eng

Conference Location

  • United States