A bipolar kinesin

Nature. 1996 Jan 18;379(6562):270-2. 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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies / immunology
  • Calcium-Binding Proteins / chemistry*
  • Drosophila melanogaster
  • Kinesin / chemistry*
  • Kinesin / immunology
  • Kinesin / isolation & purification
  • Kinesin / ultrastructure
  • Molecular Sequence Data
  • Muscle Proteins / chemistry*
  • Protein Conformation
  • Spindle Apparatus / chemistry


  • Antibodies
  • Calcium-Binding Proteins
  • Muscle Proteins
  • kinesin-II
  • Kinesin