Research in the DeLuca Lab

Mitotic cell division depends on kinetochores, which are structures that orchestrate chromosome segregation and integrate all aspects of the mitotic machinery. Kinetochores have the critical jobs of physically connecting chromosomes to spindle microtubules and regulating the strength of these connections so that erroneously-attached microtubules are released, and correctly-attached microtubules are stabilized. Kinetochores also play a key role in ensuring that cells do not exit mitosis if chromosomes fail to attach, or are incorrectly attached, to microtubules. Research in our lab focuses on understanding how kinetochores carry out these functions during mitosis to ensure genomic stability. Currently, our research questions are focused in three major areas:
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1. Generation and regulation of kinetochore-microtubule attachments.
-How does the NDC80 complex physically connect kinetochores and microtubules and how does it coordinate with other kinetochore-associated, microtubule-binding proteins to ensure formation of stable, regulatable attachments to spindle microtubules?
-How does differential Ndc80/Hec1 tail domain phosphorylation impact kinetochore functions?
-How is Aurora B kinase recruited specifically to the kinetochore to regulate attachments to microtubules during mitotic progression?

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2. Communicating kinetochore-microtubule attachment status to the spindle assembly checkpoint.

-How is kinetochore-microtubule attachment status signaled to the spindle assembly checkpoint?
-What changes occur in the protein architecture of the vertebrate kinetochore upon microtubule attachment to signal for checkpoint silencing?
-What are the molecular signals that activate Dynein to evict checkpoint proteins from kinetochores upon microtubule attachment? (In collaboration with the Markus Lab)

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3. Kinetochore de-regulation in cancer
-How does oncogenic stress induce kinetochore defects?
-What kinetochore protein activities/functions become essential for survival in transformed cells?
-Can we exploit mitotic and kinetochore vulnerabilities in cancer cells to develop new, highly-specific therapeutics?

We are using a variety of approaches and tools to attack these questions including:
-in vitro biochemical reconstitution of kinetochore and checkpoint complexes
-gene editing and traditional silence/rescue assays in cultured cells
-quantitative fluorescence microscopy assays including FRAP (fluorescence recovery after photobleaching), FRET (fluorescence resonance energy transfer), BiFC (bimolecular fluorescence complementation), and PA (photoactivation)
-single molecule dynein motility assays (in collaboration with the Markus Lab)
-live-cell time-lapse microscopy: spinning disc confocal; wide-field; light sheet -super-resolution light microscopy (STORM; ExM; SHREC)
-new immunological tools to track kinetochore protein modifications in real time