A small C-terminal sequence of Aurora B is responsible for localization and function.
Aurora B, a protein kinase required in mitosis, localizes to inner centromeres at metaphase and the spindle midzone in anaphase and is required for proper chromosome segregation and cytokinesis. Aurora A, a paralogue of Aurora B, localizes instead to centrosomes and spindle microtubules. Except for distinct N termini, Aurora B and Aurora A have highly similar sequences. We have combined small interfering RNA (siRNA) ablation of Aurora B with overexpression of truncation mutants to investigate the role of Aurora B sequence in its function. Reintroduction of Aurora B during siRNA treatment restored its localization and function. This permitted a restoration of function test to determine the sequence requirements for Aurora B targeting and function. Using this rescue protocol, neither N-terminal truncation of Aurora B unique sequence nor substitution with Aurora A N-terminal sequence affected Aurora B localization or function. Truncation of unique Aurora B C-terminal sequence from terminal residue 344 to residue 333 was without effect, but truncation to 326 abolished localization and function. Deletion of residues 326-333 completely abolished localization and blocked cells at prometaphase, establishing this sequence as critical to Aurora B function. Our findings thus establish a small sequence as essential for the distinct localization and function of Aurora B.
Scrittori
Laetitia
L
Institut Albert Bonniot, Institut National de la Santé et de la Recherche Médicale, 38706 La Tronche cedex, France.
Skoufias
Dimitrios A
DA
Hans
Fabienne
F
Gerson
Véronique
V
Sassone-Corsi
Paolo
P
Dimitrov
Stefan
S
Margolis
Robert L
RL
D000595:Amino Acid Sequence; D000705:Anaphase; D064107:Aurora Kinase B; D064127:Aurora Kinases; D018385:Centrosome / Q000648:ultrastructure; D017353:Gene Deletion; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D008677:Metaphase; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism / Q000502:physiology*; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014162:Transfection
D006657:Histones; D034741:RNA, Small Interfering; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases