Dictyostelium and Acanthamoeba myosin II assembly domains go to the cleavage furrow of Dictyostelium myosin II-null cells.
How myosin II localizes to the cleavage furrow of dividing cells is largely unknown. We show here that a 283-residue protein, assembly domain (AD)1, corresponding to the AD in the tail of Dictyostelium myosin II assembles into bundles of long tubules when expressed in myosin II-null cells and localizes to the cleavage furrow of dividing cells. AD1 mutants that do not polymerize in vitro do not go to the cleavage furrow in vivo. An assembly-competent polypeptide corresponding to the C-terminal 256 residues of Acanthamoeba myosin II also goes to the cleavage furrow of Dictyostelium myosin II-null cells. When overexpressed in wild-type cells, AD1 colocalizes with endogenous myosin II (possibly as a copolymer) in interphase, motile, and dividing cells and under caps of Con A receptors but has no effect on myosin II-dependent functions. These results suggest that neither a specific sequence, other than that required for polymerization, nor interaction with other proteins is required for localization of myosin II to the cleavage furrow.
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
Shi
S
Shu
Xiong
X
Liu
Edward D
ED
Korn
D000048:Acanthamoeba / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D004023:Dictyostelium / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D008854:Microscopy, Electron; D009154:Mutation; D024462:Myosin Type II / Q000378:metabolism*
D024462:Myosin Type II