Research Faculty

Address
630 W. 168th Street
P&S 14-453
New York, NY 10032

Phone: 212-304-5632
Fax:

jcc2210@columbia.edu
Education and Training
B.S., University of Wisconsin-Madison
Ph.D., University of North Carolina
Postdoctoral, University of Oregon
and Ludwig Institute for Cancer Research-UCSD branch



Our Lab Online
The Canman Lab
Julie C. Canman, Ph.D.
Assistant Professor of Pathology and Cell Biology
Research Summary

The Canman Lab: Obsessed with Cell Division

Accurate division of one cell into two is critical to the growth and development of an organism. Errors in cell division can lead to developmental defects, sterility, and cancer in humans. In our lab, we use a combination of genetics and quantitative live-cell imaging in the model system Caenorhabditis elegans to understand the molecular regulation and mechanics of cell division.


Research

Early Caenorhabditis elegans embryo undergoing the first mitotic cell division stained for DNA (blue), kinesin-6 family member ZEN-4 (red), and microtubules (green).


Our research can be divided into three key areas:

1) Coordination of chromosome segregation with cytokinesis

During mitosis, the physical division of one cell into two is called cytokinesis. Cytokinesis must be tightly coordinated with mitotic chromosome segregation to ensure that each daughter cell receives adequate cytoplasm and a single copy of the genome. This coordination is ensured by a set of proteins required for cytokinesis that localize on the chromosomes during metaphase and transition to the division plane during chromosome segregation, on a structure called the "central spindle". Using the power of genetics and live-cell analysis, we are studying how these central spindle-bound proteins promote efficient division between the separated chromosomes.

2) Regulation of contractile ring assembly and constriction

Cytokinesis is accomplished via constriction of an equatorially localized contractile ring composed of filamentous actin and the motor protein myosin II. Assembly and constriction of the contractile ring are dependent on the small GTPase Rho, which promotes actin polymerization and myosin II motor activation. In parallel, Rac GTPases act to inhibit contractility during cytokinesis and thus must be inactivated for cytokinesis to occur. A focus of our lab is to understand the interplay between stimulatory and inhibitory signaling that promotes efficient constriction of the contractile ring to accomplish cell division.

3) Genetics of cell division

Forward genetics is a powerful tool for both gene discovery and for identifying complex molecular interactions. In our lab, we isolate cell division-defective mutations that affect gene function in a conditional (temperature-sensitive) manner. At restrictive temperature embryonic cell division fails, but at permissive temperature the embryos develop into adulthood. The "tunable" nature of these mutants provides a sensitized background to screen for genetic disruptions that either enhance or suppress the cell division defects. We are also cloning uncharacterized mutants with exciting cell division defects using both traditional and cutting-edge genetic mapping techniques.

The mighty worm:

The tiny soil dwelling nematode Caenorhabditis elegans is a powerful genetic model system to study cell division. The embryos are optically clear and embryonic cell divisions are temporally invariant, and are thus highly amenable to quantitative live-imaging analysis upon gene disruption. Importantly, the core cell division machinery active in C. elegans is evolutionarily conserved with that in human cells. Thus, our research in C. elegans will likely lead to the identification of novel drug targets to treat human disease.



Time-lapse image montage of cytokinesis visualized with a transgenic GFP fusion protein to label the plasma membrane. In the control embryo cytokinesis completes, but the mutant embryo fails in cytokinesis leading to regression of the cleavage furrow.


Visit our lab at http://pathology.columbia.edu/canmanlab/

Selected Publications

Please click the PubMed link below to view Dr. Canman's publications:

Honors and Awards

2009
Kerr Award for Research Excellence

2006-2009
Leukemia and Lymphoma Society Special Fellow

2003-2006
Jane Coffin Childs Memorial Fund Postdoctoral Fellowship


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