TY - JOUR
T1 - Direct observation of individual tubulin dimers binding to growing microtubules
AU - Mickolajczyk, Keith J.
AU - Geyer, Elisabeth A.
AU - Kim, Tae
AU - Rice, Luke M.
AU - Hancock, William O.
N1 - Publisher Copyright:
© 2019 National Academy of Sciences. All Rights Reserved.
PY - 2019/4/9
Y1 - 2019/4/9
N2 - The biochemical basis of microtubule growth has remained elusive for over 30 years despite being fundamental for both cell division and associated chemotherapy strategies. Here, we combine interferometric scattering microscopy with recombinant tubulin to monitor individual tubulins binding to and dissociating from growing microtubule tips. We make direct, single-molecule measurements of tubulin association and dissociation rates. We detect two populations of transient dwell times and determine via binding-interface mutants that they are distinguished by the formation of one interprotofilament bond. Applying a computational model, we find that slow association kinetics with strong interactions along protofilaments best recapitulate our data and, furthermore, predicts plus-end tapering. Overall, we provide the most direct and complete experimental quantification of how microtubules grow to date.
AB - The biochemical basis of microtubule growth has remained elusive for over 30 years despite being fundamental for both cell division and associated chemotherapy strategies. Here, we combine interferometric scattering microscopy with recombinant tubulin to monitor individual tubulins binding to and dissociating from growing microtubule tips. We make direct, single-molecule measurements of tubulin association and dissociation rates. We detect two populations of transient dwell times and determine via binding-interface mutants that they are distinguished by the formation of one interprotofilament bond. Applying a computational model, we find that slow association kinetics with strong interactions along protofilaments best recapitulate our data and, furthermore, predicts plus-end tapering. Overall, we provide the most direct and complete experimental quantification of how microtubules grow to date.
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U2 - 10.1073/pnas.1815823116
DO - 10.1073/pnas.1815823116
M3 - Article
C2 - 30804205
AN - SCOPUS:85064110071
SN - 0027-8424
VL - 116
SP - 7314
EP - 7322
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 15
ER -