A bipolar kinesin

• Published in: Nature (London) Vol. 379; no. 6562; pp. 270 - 272
• Main Authors: Kashlna, A. S, Baskin, R. J, Cole, D. G, Wedaman, K. P, Saxton, W. M, Scholey, J. M
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 18.01.1996; Nature Publishing Group
• Subjects: Amino Acid Sequence; Animals; Antibodies - immunology; Biological and medical sciences; Calcium-Binding Proteins - chemistry; Cellular biology; Classical genetics, quantitative genetics, hybrids; Drosophila melanogaster; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Invertebrata; Kinesin - chemistry; Kinesin - immunology; Kinesin - isolation & purification; Kinesin - ultrastructure; Molecular biology; Molecular Sequence Data; Muscle Proteins - chemistry; Protein Conformation; Proteins; Spindle Apparatus - chemistry; Molecular motion; Purification; Insecta; Contractile protein; Homology; Drosophilidae; Arthropoda; Invertebrata; Drosophila melanogaster; Diptera; Kinesin; Nuclear protein; Aminoacid sequence
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/379270a0

Chromosome segregation during mitosis depends on the action of the mitotic spindle, a self-organizing, bipolar protein machine which uses microtubules (MTs) and their associated motors. Members of the BimC subfamily of kinesin-related MT-motor proteins are believed to be essential for the formation and functioning of a normal bipolar spindle. Here we report that KRP130, a homotetrameric BimC-related kinesin purified from Drosophila melanogaster embryos, has an unusual ultrastructure. It consists of four kinesin-related polypeptides assembled into a bipolar aggregate with motor domains at opposite ends, analogous to a miniature myosin filament. Such a bipolar 'minifilament' could crosslink spindle MTs and slide them relative to one another. We do not know of any other MT motors that have a bipolar structure.