Type II myosin involved in cytokinesis in the fission yeast, Schizosaccharomyces pombe.
Cell Motil Cytoskeleton
We have cloned an unique gene encoding the heavy chain of a type II myosin in the fission yeast, Schizosaccharomyces pombe. The myo2+ gene encodes a protein of 1526 amino acids with a predicted molecular weight of 177 kDa and containing consensus binding motifs for both essential and regulatory light chains. The S. pombe myo2+ head domain is 45% identical to myosin IIs from Saccharomyces cerevisiae and Homo sapiens and 40% identical to Drosophila melanogaster Structurally, myo2+ most closely resembles budding yeast MYO1, the tails of both myosin IIs containing a number of proline residues that are predicted to substantially disrupt the ability of these myosins to form coiled coils. The myo2+ gene is located on chromosome III, 8.3 map units from ade6+. Deletion of approximately 70% of the coding sequence of myo2+ is lethal but myo2delta spores can acquire a suppressor mutation that allows them to form viable microcolonies consisting of filaments of branched cells with aberrant septa. Overexpression of myo2+ results in the inhibition of cytokinesis; cells become elongated and multinucleate and fail to assemble a functional cytokinetic actin ring and are either aseptate or form aberrant septa. These results suggest that a contractile actin-myosin based cytokinetic mechanism appeared early in the evolution of eukaryotic cells and further emphasise the utility of fission yeast as a model organism in which to study the molecular and cellular basis of cytokinesis.
|Title:||Type II myosin involved in cytokinesis in the fission yeast, Schizosaccharomyces pombe.|
|Keywords:||Amino Acid Sequence, Animals, Bacterial Proteins, Carrier Proteins, Cell Division, Cloning, Molecular, Fungal Proteins, Gene Deletion, Gene Expression, Humans, Molecular Sequence Data, Myosin Heavy Chains, Myosin Type II, Myosin Type V, Myosins, Saccharomyces cerevisiae Proteins, Schizosaccharomyces, Schizosaccharomyces pombe Proteins, Sequence Analysis, DNA, Sequence Homology, Amino Acid|
|UCL classification:||UCL > School of Life and Medical Sciences
UCL > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > School of Life and Medical Sciences > Faculty of Life Sciences > Biosciences (Division of)
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