Minus End Depolymerization
Minus End Depolymerization - Related Videos
01:19
Actin Filament Depolymerization
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2023
Actin filaments (F-actin) are composed of actin subunits. The dissociation of actin monomers can occur from either end of F-actin. The rate of dissociation is faster from the minus-end or the pointed end, where the actin subunits exist with a bound ADP, together known as ADP-actin. The depolymerization of F-actin is aided by proteins, including the actin-depolymerizing factor (ADF) and cofilin family of proteins, gelsolin, and glia maturation factor (GMF). In F-actin, the ADF/cofilin proteins...
10:18
Extraction of Lignin with High β-O-4 Content by Mild Ethanol Extraction and Its Effect on the Depolymerization Yield
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Cited by 61 •
2019
Here, we present a protocol to perform ethanol extraction of lignin from several biomass sources. The effect of the extraction conditions on the lignin yield and β-O-4 content are presented. Selective depolymerization is performed on the obtained lignins to obtain high aromatic monomer products.
07:54
Purification of Tubulin with Controlled Posttranslational Modifications and Isotypes from Limited Sources by Polymerization-Depolymerization Cycles
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Cited by 6 •
2020
This protocol describes tubulin purification from small/medium-scale sources such as cultured cells or single mouse brains, using polymerization and depolymerization cycles. The purified tubulin is enriched in specific isotypes or has specific posttranslational modifications and can be used in in vitro reconstitution assays to study microtubule dynamics and interactions.
12:20
Preparation of Segmented Microtubules to Study Motions Driven by the Disassembling Microtubule Ends
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Cited by 24 •
2014
Microtubules are inherently unstable polymers, and their switching between growth and shortening is stochastic and difficult to control. Here we describe protocols using segmented microtubules with photoablatable stabilizing caps. Depolymerization of segmented microtubules can be triggered with high temporal and spatial resolution, thereby assisting analysis of motions with the disassembling microtubule ends.
12:38
Use of Immunolabeling to Analyze Stable, Dynamic, and Nascent Microtubules in the Zebrafish Embryo
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Cited by 1 •
2017
Immunolabeling methods to analyze distinct populations of microtubules in the developing zebrafish brain are described here, which are broadly applicable to other tissues. The first protocol outlines an optimized method for immunolabeling stable and dynamic microtubules. The second protocol provides a method to image and quantify nascent microtubules specifically.
FAQs
The critical change is exposure of GDP-tubulin at the microtubule minus end after the stabilizing GTP-tubulin lattice has been lost. GDP-tubulin does not provide the same stabilizing condition, so subunits can dissociate from that end. This molecular transition allows cells to reduce microtubule length and contributes to controlled cytoskeletal turnover.
Specialized depolymerizing proteins and other microtubule-associated factors can accelerate subunit loss at the minus end. Their activity changes the rate at which microtubules shorten, allowing cells to adjust microtubule length and organization more efficiently. This regulation is important when the cytoskeleton must be remodeled during transport, cell-shape changes, or division.
The GTP-tubulin lattice provides a stabilizing state that helps retain microtubule subunits. When that lattice is lost, the minus end exposes GDP-tubulin, creating conditions that permit dissociation. Thus, the balance between lattice stabilization and GDP-tubulin exposure helps determine whether a microtubule remains extended or undergoes shortening.
Changing the rate of minus end subunit loss changes microtubule length and, consequently, the organization of the cytoskeleton. Because microtubules help establish cellular polarity and shape, altered shortening can affect how these structures are arranged within a cell. The same regulatory relationship supports coordinated remodeling rather than uncontrolled or static microtubule organization.
Regulated shortening contributes to microtubule turnover, spindle remodeling, chromosome segregation, and cellular transport. In each setting, changing microtubule length or organization helps the cytoskeleton respond to cellular demands. These roles make minus end depolymerization relevant to both routine intracellular organization and major transitions associated with cell division.
During division, minus end depolymerization helps remodel the microtubule spindle, the cytoskeletal structure that organizes chromosome movement. Controlled loss of tubulin subunits can change spindle microtubule length and arrangement, supporting the structural adjustments required for chromosome segregation. Disrupting this regulation could therefore affect how effectively the division machinery is reorganized.
Microtubule length and organization influence the cytoskeletal framework used for cellular transport and polarity. By removing subunits from the minus end, cells can adjust that framework as their internal organization changes. This makes the process relevant not only to microtubule turnover, but also to maintaining appropriate cell shape and directional organization.
Studying this process can clarify how abnormal cytoskeletal dynamics contribute to developmental defects and diseases. Researchers can relate changes in microtubule shortening to altered length, organization, cell shape, transport, or division. These connections provide a biological context for investigating conditions in which regulated cytoskeletal behavior is disrupted.