Comparative profiling identifies C13orf3 as a component of the Ska complex required for mammalian cell division.
Proliferation of mammalian cells requires the coordinated function of many proteins to accurately divide a cell into two daughter cells. Several RNAi screens have identified previously uncharacterised genes that are implicated in mammalian cell division. The molecular function for these genes needs to be investigated to place them into pathways. Phenotypic profiling is a useful method to assign putative functions to uncharacterised genes. Here, we show that the analysis of protein localisation is useful to refine a phenotypic profile. We show the utility of this approach by defining a function of the previously uncharacterised gene C13orf3 during cell division. C13orf3 localises to centrosomes, the mitotic spindle, kinetochores, spindle midzone, and the cleavage furrow during cell division and is specifically phosphorylated during mitosis. Furthermore, C13orf3 is required for centrosome integrity and anaphase onset. Depletion by RNAi leads to mitotic arrest in metaphase with an activation of the spindle assembly checkpoint and loss of sister chromatid cohesion. Proteomic analyses identify C13orf3 (Ska3) as a new component of the Ska complex and show a direct interaction with a regulatory subunit of the protein phosphatase PP2A. All together, these data identify C13orf3 as an important factor for metaphase to anaphase progression and highlight the potential of combined RNAi screening and protein localisation analyses.
Theis
Mirko
M
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Slabicki
Mikolaj
M
Junqueira
Magno
M
Paszkowski-Rogacz
Maciej
M
Sontheimer
Jana
J
Kittler
Ralf
R
Heninger
Anne-Kristine
AK
Glatter
Timo
T
Kruusmaa
Kristi
K
Poser
Ina
I
Hyman
Anthony A
AA
Pisabarro
M Teresa
MT
Gstaiger
Matthias
M
Aebersold
Rudolf
R
Shevchenko
Andrej
A
Buchholz
Frank
F
D018797:Cell Cycle Proteins; D018385:Centrosome / Q000737:chemistry*; D048749:Cytokinesis; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000737:chemistry*; D008869:Microtubule-Associated Proteins / Q000032:analysis*; D010766:Phosphorylation; D034741:RNA, Small Interfering / Q000235:genetics; D008941:Spindle Apparatus / Q000737:chemistry*
D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; D034741:RNA, Small Interfering; C541140:Ska3 protein, human