Microtubules are important components of the cytoskeleton of eukaryotic cells, and participate in the development and maintenance of cell shape and in many kinds of intracellular movement. They are prominent in the central nervous system where they are especially important in the organization and function of axonal and dendritic processes of neurons. Microtubules exhibit a wide variety of polymerization behaviors in vitro and in cells, and there is strong reason to believe that the various polymerization behaviors are important in microtubule function. Microtubule functions such as those related to the organization and development of axons and dendrites may be determined and regulated by modulation of the assembly and disassemble reactions at microtubule ends. The role of polymerization dynamics in the function of microtubules at a mechanistic level is not understood. With a focus on brain microtubule systems, the main strategy of this proposal is to investigate the dynamics of tubulin addition and loss at microtubule ends in vitro, with the goals of understanding the mechanisms that govern tubulin addition and loss and identifying and elucidating mechanistically the actions of microtubule- associated proteins that control assembly and disassembly dynamics in neuronal cells. A combination of procedures will be employed that can distinguish tubulin addition and loss events at the individual microtubule ends. The dynamics of tubulin addition and loss at the ends of microtubules composed of unmodified and posttranslationally-modified brain tubulins (detyrosinated, glutamylated, ADP-ribosylated) and specific unmodified and modified (phosphorylated) neuronal MAPs will be examined. The work will focus on the actions of MAP-2 and Tau, two prominent neuronal microtubule-associated proteins that are important in the development, organization, and functions of dendrites and axons, respectively. The work will also focus on the role of GTP hydrolysis in microtubule polymerization. The objective is to characterize the flux and dynamic instability parameters of the microtubules, and to determine to what extent and how specific microtubule-associated proteins, specific tubulin isotypes, posttranslational modifications of tubulin and microtubule- associated proteins, and the drug colchicine, modulate and regulate microtubule polymerization.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS013560-17
Application #
3395262
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1978-07-01
Project End
1995-12-31
Budget Start
1993-01-01
Budget End
1993-12-31
Support Year
17
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of California Santa Barbara
Department
Type
Schools of Arts and Sciences
DUNS #
City
Santa Barbara
State
CA
Country
United States
Zip Code
93106
Choi, Myung Chul; Chung, Peter J; Song, Chaeyeon et al. (2017) Paclitaxel suppresses Tau-mediated microtubule bundling in a concentration-dependent manner. Biochim Biophys Acta Gen Subj 1861:3456-3463
Chung, Peter J; Song, Chaeyeon; Deek, Joanna et al. (2016) Tau mediates microtubule bundle architectures mimicking fascicles of microtubules found in the axon initial segment. Nat Commun 7:12278
Chung, Peter J; Choi, Myung Chul; Miller, Herbert P et al. (2015) Direct force measurements reveal that protein Tau confers short-range attractions and isoform-dependent steric stabilization to microtubules. Proc Natl Acad Sci U S A 112:E6416-25
Ojeda-Lopez, Miguel A; Needleman, Daniel J; Song, Chaeyeon et al. (2014) Transformation of taxol-stabilized microtubules into inverted tubulin tubules triggered by a tubulin conformation switch. Nat Mater 13:195-203
Needleman, Daniel J; Ojeda-Lopez, Miguel A; Raviv, Uri et al. (2013) Ion specific effects in bundling and depolymerization of taxol-stabilized microtubules. Faraday Discuss 166:31-45
Lopus, Manu; Manatschal, Cristina; Buey, Ruben M et al. (2012) Cooperative stabilization of microtubule dynamics by EB1 and CLIP-170 involves displacement of stably bound P(i) at microtubule ends. Biochemistry 51:3021-30
Lopus, Manu (2011) Antibody-DM1 conjugates as cancer therapeutics. Cancer Lett 307:113-8
Davé, Rahul H; Saengsawang, Witchuda; Lopus, Manu et al. (2011) A molecular and structural mechanism for G protein-mediated microtubule destabilization. J Biol Chem 286:4319-28
Safinya, Cyrus R; Raviv, Uri; Needleman, Daniel J et al. (2011) Nanoscale assembly in biological systems: from neuronal cytoskeletal proteins to curvature stabilizing lipids. Adv Mater 23:2260-70
Kiris, Erkan; Ventimiglia, Donovan; Sargin, Mehmet E et al. (2011) Combinatorial Tau pseudophosphorylation: markedly different regulatory effects on microtubule assembly and dynamic instability than the sum of the individual parts. J Biol Chem 286:14257-70

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