Microtubule Nucleation by the Centrosome

My research interest is to study the structural details by which the eukaryotic centrosome controls the cell's microtubule infrastructure. The centrosome anchors the microtubule network by providing nucleation sites for polymerization of tubulin monomers, whose cytoplasmic concentrations are too low for spontaneous, non-templated nucleation. The g-tubulin ring complex (g-TuRC) serves as this microtubule seed, and is recruited to the centrosome to nucleate plus-end microtubule growth outward from the organelle. I am interested in understanding the protein components required for this process, the architecture of g-TuRC and the mechanism by which it seeds microtubule growth, and the elements that control g-TuRC's centrosomal localization and nucleating activity in a cell-cycle-driven manner. I hope to use protein microsequencing (in collaboration with John Yates, Scripps Research Inst.) and cell biological assays reconstituting microtubule aster formation from minimal centrosome components to complement X-ray crystallography and electron microscopy data to attack these questions.

Publications

Trammell MA, Mahoney NM, Agard DA, Vale RD., "Mob4 plays a role in spindle focusing in Drosophila S2 cells." J Cell Sci. (2008), 121(8), 1284-92. (pdf)