Mechanisms Ensuring Genome Stability During Cell Division

A major and long-standing subject of investigation in the Desai lab is the kinetochore, the protein machine that is built on centromeric chromatin to orchestrate chromosome segregation. The lab has dedicated significant effort towards understanding how dynamic coupling between kinetochores and spindle microtubules is achieved and how this coupling is integrated with regulatory mechanisms ensuring accuracy in chromosome segregation.  The work on this topic has led the lab into new areas including chemical biology approaches targeting cell division processes, control of cell cycle progression both prior to and during mitosis, pathways for spindle assembly, and linking understanding of cell division mechanisms to cancer cell aneuploidy.

Kim T, Lara-Gonzalez P, Prevo B, Meitinger F, Cheerambathur DK, Oegema K, Desai A. (2017) Kinetochores accelerate or delay APC/C activation by directing Cdc20 to opposing fates. Genes Dev. 31(11):1089-1094

Santaguida S, Richardson A, Iyer DR, M'Saad O, Zasadil L, Knouse KA, Wong YL, Rhind N, Desai A, Amon A. (2017) Chromosome Mis-segregation Generates Cell-Cycle-Arrested Cells with Complex Karyotypes that Are Eliminated by the Immune System. Dev Cell. 41(6):638-651.e635

Cheerambathur DK, Prevo B, Hattersley N, Lewellyn L, Corbett KD, Oegema K, Desai A. (2017) Dephosphorylation of the Ndc80 Tail Stabilizes Kinetochore-Microtubule Attachments via the Ska Complex. Dev Cell. 41(4):424-437.e424

Hattersley N, Cheerambathur D, Moyle M, Stefanutti M, Richardson A, Lee KY, Dumont J, Oegema K, Desai A. (2016) A Nucleoporin Docks Protein Phosphatase 1 to Direct Meiotic Chromosome Segregation and Nuclear Assembly. Dev Cell. 38(5):463-477

Folco HD, Campbell CS, May K, Espinoza C, Oegema K, Ren B, Hardwick K, Grewal S, Desai A. (2015) The N-terminal tail of CENP-A confers epigenetic stability to centromeres via the CENP-T branch of the CCAN in fission yeast.  Curr Biol. 25(3):348-56

Cheerambathur DK, Gassmann R, Cook B, Oegema K, Desai A. (2013) Crosstalk between microtubule attachment complexes ensures accurate chromosome segregation. Science 342(6163):1239-1242

Campbell CS, Desai A. (2013) Tension sensing by Aurora B kinase is independent of survivin-based centromere localization. Nature. 497(7447):118-21

Cytokinesis

The Oegema lab has a long-standing interest in cytokinesis, the process that completes cell division by partitioning the contents of the mother cell to the two daughters. The lab is interested in regulatory mechanisms controlling the formation of the transient contractile ring between the separated chromosome masses and the mechanics of contractile ring assembly and constriction.

Khaliullin RN, Green RA, Shi LZ, Gomez-Cavazos JS, Berns MW, Desai A, Oegema K. (2018) A positive-feedback-based mechanism for constriction rate acceleration during cytokinesis in Caenorhabditis elegans. Elife. 7:e36073

Lee KY, Green RA, Gutierrez E, Gomez-Cavazos JS, Kolotuev I, Wang S, Desai A, Groisman A, Oegema K. (2018) CYK-4 functions independently of its centralspindlin partner ZEN-4 to cellularize oocytes in germline syncytia. Elife. 7: e36919

Mangal S, Sacher J, Kim T, Osorio DS, Motegi F, Carvalho AX, Oegema K, Zanin E. (2018) TPXL-1 activates Aurora A to clear contractile ring components from the polar cortex during cytokinesis. J Cell Biol. 217(3):837-848

Zanin E, Desai A, Poser I, Toyoda Y, Andree C, Moebius C, Bickle M, Conradt B, Piekny A, Oegema K. (2013) A conserved RhoGAP limits M phase contractility and coordinates with microtubule asters to confine RhoA during cytokinesis. Dev Cell. 26(5):496-510

Centrosomes and Spindle Assembly

Centrosomes are cellular organelles composed of a mother centriole or a mother-daughter pair surrounded by pericentriolar material that nucleates and anchors microtubules. During mitosis, centrosomes accelerate assembly of the microtubule-based mitotic spindle that segregates the replicated chromosomes to the two daughter cells. The Oegema and Desai labs are interested in the mechanisms that control the assembly of centrioles and centrosomes and how these mechanisms are integrated with microtubule generation during spindle assembly.  The Oegema lab has also investigated non-centrosomal microtubule assembly mechanisms in differentiated cells, employing C. elegans tissues as models.

Wang S, Wu D, Quintin S, Green RA, Cheerambathur DK, Ochoa SD, Desai A, Oegema K. (2015) NOCA-1 Functions with γ-tubulin and in parallel to Patronin to assemble non-centrosomal microtubule arrays in C. elegans. Elife. 4e08649

Wong YL, Anzola JV, Davis RL, Yoon M, Motamedi A, Kroll A, Seo CP, Hsia JE, Kim SK, Mitchell JW, Mitchell BJ, Desai A, Gahman TC, Shiau AK, Oegema K. (2015) Reversible centriole depletion with an inhibitor of Polo-like kinase 4. Science. 348(6239):1155-1160

Woodruff JB, Wueseke O, Viscardi V, Mahamid J, Ochoa SD, Bunkenborg J, Widlund PO, Pozniakovsky A, Zanin E, Bahmanyar S, Zinke A, Hong SH, Decker M, Baumeister W, Andersen JS, Oegema K, Hyman AA. (2015) Centrosomes. Regulated assembly of a supramolecular centrosome scaffold in vitro. Science. 348(6236):808-812

Shimanovskaya E, Viscardi V, Lesigang J, Lettman MM, Qiao R, Svergun DI, Round A, Oegema K, Dong G. (2014) Structure of the C. elegans ZYG-1 cryptic polo box suggests a conserved mechanism for centriolar docking of Plk4 kinases. Structure. 22(8):1090-1104

Lettman MM, Wong YL, Viscardi V, Niessen S, Chen SH, Shiau AK, Zhou H, Desai A, Oegema K. (2013) Direct binding of SAS-6 to ZYG-1 recruits SAS-6 to the mother centriole for cartwheel assembly. Dev Cell. 25(3):284-298

Targeting mitosis in cancer

Work from our labs and others delineated the pathway of centrosome duplication and showed that duplication is critically dependent on the kinase Plk4. To investigate the consequences of centrosome removal and explore the potential of centrosome removal as a therapy in cancer, we collaborated with the Small Molecule Development Group in the Ludwig Institute for Cancer Research to develop centrinone, the first specific, potent, cellularly active Plk4 inhibitor. Centrinone prevents centrosome duplication and depletes centrosomes from dividing human cells. Experiments using centrinone have revealed striking differences in how cells respond to centrosome removal and have identified key molecular determinants that control this response. In current work, we are investigating the molecular pathways that control the response to centrosome removal in different cancer types. We are also initiating broader approaches aimed at understanding how the mitotic machinery is rewired in different cell types to identify other ways that mitosis can be manipulated to kill cancer cells.

Oegema K, Davis RL, Lara-Gonzalez P, Desai A, Shiau AK. (2018) CFI-400945 is not a selective cellular PLK4 inhibitor. Proc Natl Acad Sci U S A. 115(46):E10808-e10809

Meitinger F, Anzola JV, Kaulich M, Richardson A, Stender JD, Benner C, Glass CK, Dowdy SF, Desai A, Shiau AK, Oegema K. (2016) 53BP1 and USP28 mediate p53 activation and G1 arrest after centrosome loss or extended mitotic duration. J Cell Biol. 214(2):155-166

Wong YL, Anzola JV, Davis RL, Yoon M, Motamedi A, Kroll A, Seo CP, Hsia JE, Kim SK, Mitchell JW, Mitchell BJ, Desai A, Gahman TC, Shiau AK, Oegema K. (2015) Reversible centriole depletion with an inhibitor of Polo-like kinase 4. Science. 348(6239):1155-1160  

High-content functional Screening

A long-standing focus of the Oegema lab is the development of high-content imaging-based functional screening approaches. Karen Oegema was an integral member of the team that conducted the first genome-wide RNAi screen by imaging the first two embryonic divisions of C. elegans. A subsequent screen, conducted in the Oegema lab, employed germline morphology as a readout for classifying all of the genes required for embryo production.  Currently, the lab is  using high-content approaches to classify mitotic mechanisms in different human cell types and to functionally profile the ~2700 C. elegans genes specifically required for tissue specification and morphogenesis during embryonic development.

Sonnichsen B, Koski LB, Walsh A, Marschall P, Neumann B, Brehm M, Alleaume AM, Artelt J, Bettencourt P, Cassin E, Hewitson M, Holz C, Khan M, Lazik S, Martin C, Nitzsche B, Ruer M, Stamford J, Winzi M, Heinkel R, Roder M, Finell J, Hantsch H, Jones SJ, Jones M, Piano F, Gunsalus KC, Oegema K, Gonczy P, Coulson A, Hyman AA, Echeverri CJ. (2005) Full-genome RNAi profiling of early embryogenesis in Caenorhabditis elegans. Nature. 434(7032):462-469

Green RA, Kao HL, Audhya A, Arur S, Mayers JR, Fridolfsson HN, Schulman M, Schloissnig S, Niessen S, Laband K, Wang S, Starr DA, Hyman AA, Schedl T, Desai A, Piano F, Gunsalus KC, Oegema K. (2011) A high-resolution C. elegans essential gene network based on phenotypic profiling of a complex tissue. Cell. 145(3):470-482

Meitinger F, Anzola JV, Kaulich M, Richardson A, Stender JD, Benner C, Glass CK, Dowdy SF, Desai A, Shiau AK, Oegema K. (2016) 53BP1 and USP28 mediate p53 activation and G1 arrest after centrosome loss or extended mitotic duration. J Cell Biol. 214(2):155-166