Centrosomes are vital mechanical hubs in cells that sustain load-bearing attachments to microtubules and orchestrate arrays of microtubules to support cell motility, nuclear positioning, mitotic spindle assembly, and chromosome segregation. Mutations affecting the ability of centrosomes to sustain or regulate attachments of microtubules are correlated with an increase in genome instability and progression of cancers. Despite this important role and the considerable forces that centrosome-microtubule interactions are thought to sustain in vivo, microtubule attachments to centrosomes have never been mechanically investigated in any organism. Consequently, the extent to which these interactions may be mechanically regulated has also never been investigated. In a collaborative project with the Asbury, Davis, and Agard labs, this work aims to reveal the molecular interactions by which centrosomes sustain, sense, and respond to forces transmitted by microtubules. Centrosome-microtubule interactions will be reconstituted in vitro and individually interrogated using a combination of single molecule laser trapping, total internal reflection fluorescence (TIRF) microscopy, and molecular cell biology techniques. Through the combination of biophysical expertise in the Asbury lab with the biochemical and structural expertise of the Davis and Agard labs, this proposal will determine the role of specific molecular components in sustaining and regulating attachments of microtubules to centrosomes more precisely and directly than has ever been done before. Revealing how centrosomes sustain, sense, and respond to mechanical forces will shed light on how these pathways fail in human diseases such as cancer and may ultimately lead to the identification of new chemotherapeutic targets.

Public Health Relevance

Centrosomes are vital mechanical hubs in cells and sustain load-bearing attachments to microtubules that are essential for cell viability and division. By using single-molecule and molecular cell biology methods to interrogate individual microtubule attachments to centrosomes; this project will reveal how centrosomes sustain; sense; and regulate the forces transmitted by microtubules. Revealing how centrosomes normally maintain and regulate attachments to microtubules will shed light on how these pathways fail in human diseases such as cancer and may lead to the identification of new chemotherapeutic targets.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32GM109493-02
Application #
8790903
Study Section
Special Emphasis Panel (ZRG1-F05-D (21))
Program Officer
Sakalian, Michael
Project Start
2014-01-01
Project End
2016-12-31
Budget Start
2015-01-01
Budget End
2015-12-31
Support Year
2
Fiscal Year
2015
Total Cost
$54,194
Indirect Cost
Name
University of Washington
Department
Physiology
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Fong, Kimberly K; Sarangapani, Krishna K; Yusko, Erik C et al. (2017) Direct measurement of the strength of microtubule attachment to yeast centrosomes. Mol Biol Cell 28:1853-1861
Yusko, Erik C; Asbury, Charles L (2014) Force is a signal that cells cannot ignore. Mol Biol Cell 25:3717-25