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Publications and Presentations
Publications
Tau Induces Taxol to Bind Microtubules Cooperatively
Accepted for publication in Proceedings of the National Academy of Sciences ABSRTACT: Taxol and tau are two ligands which stabilize the microtubule lattice. Taxol is an anti-mitotic drug that binds b tubulin in the microtubule interior. Tau is a microtubule-associated protein that binds both a and b tubulin on the microtubule exterior. Both taxol and tau reduce microtubule dynamics and promote tubulin polymerization. Tau alone also acts as a buttress to bundle, stiffen, and space microtubules. A structural study recently suggested that taxol and tau may interact by binding to the same site. Here, we report that tau induces taxol to bind microtubules cooperatively dependent on the tau concentration using fluorescence recovery after photobleaching. We develop a model that correctly fits the data in the absence of tau and yields a measure of taxol cooperativity when tau is present.
Mobility of Taxol in Microtubule Bundles
Accepted for publication in Biophysical Journal; Vol 84, June 2003. ABSTRACT: Mobility of taxol inside microtubules was investigated using fluorescence recovery after photobleaching (FRAP) on flow-aligned bundles. Bundles were made of microtubules with either GMPCPP or GTP at the exchangeable site on the tubulin dimer. Recovery times were sensitive to bundle thickness and packing, indicating that the microtubule wall is permeable to taxol. The density of open binding sites along a microtubule was varied by controlling the concentration of taxol in solution. With > 63% sites occupied, recovery times were independent of taxol concentration and, therefore, inversely proportional to the microscopic dissociation rate, koff. It was found that 10 koffGMPCPP ~ koffGTP, consistent with, but not fully accounting for, the difference in equilibrium constants for taxol on GMPCPP and GTP microtubules. With < 63% sites occupied, recovery times decreased as for both types of microtubules. We conclude that the diffusion of taxol inside the microtubule bundle is hindered by rebinding events when open sites are within ~7 nm of each other. PDF preprint of paper PDF
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Presentations
"Tau Induces Taxol to Bind Microtubules Cooperatively"
"Tau Induces Taxol to Bind Microtubules Cooperatively"
"Tau Induces Taxol to Bind Microtubules Cooperatively"
"Diffusion Inside and In Between Microtubules"
"Using FRAP on Microtubules - recent work update"
"Macromolecular Diffusion In and Around Microtubules"
"Affects of Tau on Taxol Mobility"
"Mobility of Taxol Inside Microtubule Bundles"
"Mobility of Taxol Inside Microtubule Bundles"
"Random Walks Through Microtubules"
"Random Walks Through Microtubules: Mobility of Taxol Inside
Microtubule Bundles"
"Mobility of Taxol in Microtubule Bundles"
Awards, Fellowships, and Research Opportunities
UCSB Affiliates Barbarba S. Uehling Graduate Dissertation Fellowship, declined
Materials Research Laboratory Graduate Student Travel Grant,
Ferrando-Fithian Fellowship for Outstanding Woman in Physics,
Graduate Assistance in the Areas of National Need (GAANN) Fellowship,
Phyllis Flemming Physics Prize for Outstanding Physics Major,
Jerome A. Schiff Fellowship for Thesis Work,
Massachusetts Spaces Grant Consortium Thesis Fellowship,
Hughes Research Travel Grant,
Outstanding Student Presentation,
NASA Reduced Gravity Student Flight Opportunities Program,
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