Control mechanisms of microtubule overlap regions

Aniek Jongerius

Research output: Thesisinternal PhD, WU

Abstract

Microtubule organization in cells is an important process. An example of careful microtubule organization is the mitotic spindle. The spindle is a bipolar structure with microtubules emanating from the poles at both sides. These microtubules form antiparallel overlaps in the centre of the spindle where they are bundled by bundling proteins. The overlaps are centred in the spindle and their constant length is regulated. The overlaps are important for the stability of the microtubule network, without bundling proteins the overlaps are lost and the spindle collapses. The antiparallel overlaps are also the site where microtubules slide apart to induce spindle elongation. Sliding is induced by tetrameric motor proteins that can bind to two bundled microtubules. Spindle elongation also requires microtubule growth at the overlaps. All these different functions at the overlap, sliding, growth/shrinkage and bundling, have to cooperate to maintain overlap length. While sliding reduces overlap length, growth will increase overlap length. These activities have to be coordinated for the maintenance of a constant overlap length. We propose that a feedback mechanism is present where growth of the microtubules is limiting the sliding in the overlap. This would prevent sliding when the overlap decreases and helps to maintain the overlap. We designed in vitro experiments to make antiparallel overlaps in vitro. In these experiments we use purified proteins from S. pombe. We combine ase1 and klp9 in a relative sliding assay to mimic the sliding in the midzone. In our experiments we combine relative sliding with dynamic microtubules for the first time. This allows us to test how these activities are coordinated. In other experiments we combine ase1 and cls1 with dynamic microtubules to see if the rescue activity of cls1 can be confined to the overlaps. Furthermore, interactions between motor proteins and diffusive proteins are investigated on single microtubules.

Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Janson, Marcel, Promotor
Award date5 Jul 2017
Place of PublicationWageningen
Publisher
Print ISBNs9789463436113
DOIs
Publication statusPublished - 2017

Fingerprint

microtubules
proteins
mitotic spindle apparatus
shrinkage

Keywords

  • microtubules
  • cellular biology
  • plant cell biology
  • models
  • cells

Cite this

Jongerius, A. (2017). Control mechanisms of microtubule overlap regions. Wageningen: Wageningen University. https://doi.org/10.18174/417957
Jongerius, Aniek. / Control mechanisms of microtubule overlap regions. Wageningen : Wageningen University, 2017. 133 p.
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title = "Control mechanisms of microtubule overlap regions",
abstract = "Microtubule organization in cells is an important process. An example of careful microtubule organization is the mitotic spindle. The spindle is a bipolar structure with microtubules emanating from the poles at both sides. These microtubules form antiparallel overlaps in the centre of the spindle where they are bundled by bundling proteins. The overlaps are centred in the spindle and their constant length is regulated. The overlaps are important for the stability of the microtubule network, without bundling proteins the overlaps are lost and the spindle collapses. The antiparallel overlaps are also the site where microtubules slide apart to induce spindle elongation. Sliding is induced by tetrameric motor proteins that can bind to two bundled microtubules. Spindle elongation also requires microtubule growth at the overlaps. All these different functions at the overlap, sliding, growth/shrinkage and bundling, have to cooperate to maintain overlap length. While sliding reduces overlap length, growth will increase overlap length. These activities have to be coordinated for the maintenance of a constant overlap length. We propose that a feedback mechanism is present where growth of the microtubules is limiting the sliding in the overlap. This would prevent sliding when the overlap decreases and helps to maintain the overlap. We designed in vitro experiments to make antiparallel overlaps in vitro. In these experiments we use purified proteins from S. pombe. We combine ase1 and klp9 in a relative sliding assay to mimic the sliding in the midzone. In our experiments we combine relative sliding with dynamic microtubules for the first time. This allows us to test how these activities are coordinated. In other experiments we combine ase1 and cls1 with dynamic microtubules to see if the rescue activity of cls1 can be confined to the overlaps. Furthermore, interactions between motor proteins and diffusive proteins are investigated on single microtubules.",
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year = "2017",
doi = "10.18174/417957",
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Jongerius, A 2017, 'Control mechanisms of microtubule overlap regions', Doctor of Philosophy, Wageningen University, Wageningen. https://doi.org/10.18174/417957

Control mechanisms of microtubule overlap regions. / Jongerius, Aniek.

Wageningen : Wageningen University, 2017. 133 p.

Research output: Thesisinternal PhD, WU

TY - THES

T1 - Control mechanisms of microtubule overlap regions

AU - Jongerius, Aniek

N1 - WU thesis 6709 Author's name on overleaf title page A.W. Jongerius Includes bibliographical references. - With summary in English

PY - 2017

Y1 - 2017

N2 - Microtubule organization in cells is an important process. An example of careful microtubule organization is the mitotic spindle. The spindle is a bipolar structure with microtubules emanating from the poles at both sides. These microtubules form antiparallel overlaps in the centre of the spindle where they are bundled by bundling proteins. The overlaps are centred in the spindle and their constant length is regulated. The overlaps are important for the stability of the microtubule network, without bundling proteins the overlaps are lost and the spindle collapses. The antiparallel overlaps are also the site where microtubules slide apart to induce spindle elongation. Sliding is induced by tetrameric motor proteins that can bind to two bundled microtubules. Spindle elongation also requires microtubule growth at the overlaps. All these different functions at the overlap, sliding, growth/shrinkage and bundling, have to cooperate to maintain overlap length. While sliding reduces overlap length, growth will increase overlap length. These activities have to be coordinated for the maintenance of a constant overlap length. We propose that a feedback mechanism is present where growth of the microtubules is limiting the sliding in the overlap. This would prevent sliding when the overlap decreases and helps to maintain the overlap. We designed in vitro experiments to make antiparallel overlaps in vitro. In these experiments we use purified proteins from S. pombe. We combine ase1 and klp9 in a relative sliding assay to mimic the sliding in the midzone. In our experiments we combine relative sliding with dynamic microtubules for the first time. This allows us to test how these activities are coordinated. In other experiments we combine ase1 and cls1 with dynamic microtubules to see if the rescue activity of cls1 can be confined to the overlaps. Furthermore, interactions between motor proteins and diffusive proteins are investigated on single microtubules.

AB - Microtubule organization in cells is an important process. An example of careful microtubule organization is the mitotic spindle. The spindle is a bipolar structure with microtubules emanating from the poles at both sides. These microtubules form antiparallel overlaps in the centre of the spindle where they are bundled by bundling proteins. The overlaps are centred in the spindle and their constant length is regulated. The overlaps are important for the stability of the microtubule network, without bundling proteins the overlaps are lost and the spindle collapses. The antiparallel overlaps are also the site where microtubules slide apart to induce spindle elongation. Sliding is induced by tetrameric motor proteins that can bind to two bundled microtubules. Spindle elongation also requires microtubule growth at the overlaps. All these different functions at the overlap, sliding, growth/shrinkage and bundling, have to cooperate to maintain overlap length. While sliding reduces overlap length, growth will increase overlap length. These activities have to be coordinated for the maintenance of a constant overlap length. We propose that a feedback mechanism is present where growth of the microtubules is limiting the sliding in the overlap. This would prevent sliding when the overlap decreases and helps to maintain the overlap. We designed in vitro experiments to make antiparallel overlaps in vitro. In these experiments we use purified proteins from S. pombe. We combine ase1 and klp9 in a relative sliding assay to mimic the sliding in the midzone. In our experiments we combine relative sliding with dynamic microtubules for the first time. This allows us to test how these activities are coordinated. In other experiments we combine ase1 and cls1 with dynamic microtubules to see if the rescue activity of cls1 can be confined to the overlaps. Furthermore, interactions between motor proteins and diffusive proteins are investigated on single microtubules.

KW - microtubuli

KW - celbiologie

KW - plantencelbiologie

KW - modellen

KW - cellen

KW - microtubules

KW - cellular biology

KW - plant cell biology

KW - models

KW - cells

U2 - 10.18174/417957

DO - 10.18174/417957

M3 - internal PhD, WU

SN - 9789463436113

PB - Wageningen University

CY - Wageningen

ER -

Jongerius A. Control mechanisms of microtubule overlap regions. Wageningen: Wageningen University, 2017. 133 p. https://doi.org/10.18174/417957