An engineered minimal chromosomal passenger complex reveals a role for INCENP/Sli15 spindle association in chromosome biorientation.
The four-subunit chromosomal passenger complex (CPC), whose enzymatic subunit is Aurora B kinase, promotes chromosome biorientation by detaching incorrect kinetochore-microtubule attachments. In this study, we use a combination of truncations and artificial dimerization in budding yeast to define the minimal CPC elements essential for its biorientation function. We engineered a minimal CPC comprised of the dimerized last third of the kinase-activating Sli15/INCENP scaffold and the catalytic subunit Ipl1/Aurora B. Although native Sli15 is not oligomeric, artificial dimerization suppressed the biorientation defect and lethality associated with deletion of a majority of its microtubule-binding domain. Dimerization did not act through a physical clustering-based kinase activation mechanism but instead promoted spindle association, likely via a putative helical domain in Sli15 that is essential even when dimerized and is required to target kinetochore substrates. Based on the engineering and characterization of a minimal CPC, we suggest that spindle association is important for active Ipl1/Aurora B complexes to preferentially destabilize misattached kinetochores.
Department of Chromosome Biology, Max F. Perutz Laboratories, University of Vienna, 1030 Vienna, Austria.
Sarah
S
Fink
Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093.|Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
Kira
K
Turnbull
Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093 christopher.campbell@univie.ac.at abdesai@ucsd.edu.|Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
Arshad
A
Desai
Department of Chromosome Biology, Max F. Perutz Laboratories, University of Vienna, 1030 Vienna, Austria christopher.campbell@univie.ac.at abdesai@ucsd.edu.
Christopher S
0000-0002-3927-344X
CS
Campbell
D064107:Aurora Kinase B / Q000378:metabolism; D064127:Aurora Kinases / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D045584:Chromosome Positioning / Q000502:physiology*; D020090:Chromosome Segregation / Q000502:physiology; D002875:Chromosomes / Q000378:metabolism / Q000502:physiology*; D005656:Fungal Proteins / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism / Q000502:physiology; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D004718:Saccharomycetales / Q000378:metabolism / Q000502:physiology*; D008941:Spindle Apparatus / Q000378:metabolism* / Q000502:physiology*
D002868:Chromosomal Proteins, Non-Histone; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008869:Microtubule-Associated Proteins; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases