Targeted movement of cell end factors in fission yeast.
Kinesins are microtubule-based motor proteins that transport cargo to specific locations within the cell. However, the mechanisms by which cargoes are directed to specific cellular locations have remained elusive. Here, we investigated the in vivo movement of the Schizosaccharomyces pombe kinesin Tea2 to establish how it is targeted to microtubule tips and cell ends. Tea2 is loaded onto microtubules in the middle of the cell, in close proximity to the nucleus, and then travels using its intrinsic motor activity primarily at the tips of polymerizing microtubules. The microtubule-associated protein Mal3, an EB1 homologue, is required for loading and/or processivity of Tea2 and this function can be substituted by human EB1. In addition, the cell-end marker Tea1 is required to anchor Tea2 to cell ends. Movement of Tea1 and the CLIP170 homologue Tip1 to cell ends is abolished in Tea2 rigor (ATPase) mutants. We propose that microtubule-based transport from the vicinity of the nucleus to cell ends can be precisely regulated, with Mal3 required for loading/processivity, Tea2 for movement and Tea1 for cell-end anchoring.
Browning
Heidi
H
Cell Cycle Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3PX, UK. browninh@andrew.cmu.edu
Hackney
David D
DD
Nurse
Paul
P
D000251:Adenosine Triphosphatases / Q000172:deficiency / Q000235:genetics; D002352:Carrier Proteins / Q000378:metabolism; D016764:Cell Polarity / Q000502:physiology*; D002478:Cells, Cultured; D006023:Glycoproteins / Q000378:metabolism; D006360:Heat-Shock Proteins; D007381:Intermediate Filament Proteins; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D020409:Molecular Motor Proteins / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D021381:Protein Transport / Q000502:physiology*; D012568:Schizosaccharomyces / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism
D002352:Carrier Proteins; C405804:EB1 microtubule binding proteins; D006023:Glycoproteins; D006360:Heat-Shock Proteins; D007381:Intermediate Filament Proteins; C108851:Mal3 protein, S pombe; D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D029702:Schizosaccharomyces pombe Proteins; C432671:Tea1 protein, S pombe; C415481:Tea2 protein, S pombe; C114142:tip1 protein, S pombe; D000251:Adenosine Triphosphatases