Related Experiment Video
Updated: Nov 10, 2025
09:39
Quantitative Immunofluorescence Assay to Measure the Variation in Protein Levels at Centrosomes
Published on: December 20, 2014
15.5K
14-3-3γ prevents centrosome duplication by inhibiting NPM1 function
Arunabha Bose1,2, Kruti Modi1, Suchismita Dey3
1Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Navi Mumbai, India.
Summary
Two acidic residues in 14-3-3 proteins regulate complex formation with ligands. Specific mutations (D129A, E136A) oppositely affect centrosome duplication by altering binding to NPM1.
Area of Science:
- Molecular Biology
- Cell Biology
- Protein Interactions
Background:
- 14-3-3 proteins are crucial regulators that bind phosphoserine motifs.
- The precise mechanisms governing 14-3-3/ligand complex dynamics are not fully understood.
- Centrosome duplication is a tightly regulated process essential for cell division.
Purpose of the Study:
- To elucidate the molecular mechanisms of 14-3-3 protein complex formation and dissociation.
- To investigate the role of specific conserved acidic residues in the 14-3-3 binding pocket.
- To determine the impact of these residues on centrosome duplication regulation.
Main Methods:
- Site-directed mutagenesis of conserved acidic residues (D129, E136) in 14-3-3 proteins.
- Assessment of centrosome duplication and amplification.
- Analysis of protein-ligand complex formation with Nucleophosmin (NPM1).
Main Results:
- Mutating D129 to alanine (D129A) inhibited centrosome duplication.
- Mutating E136 to alanine (E136A) stimulated centrosome amplification.
- Differential binding of D129A and E136A mutants to NPM1 explained the opposing effects on centrosome duplication.
Conclusions:
- Identified a novel role for 14-3-3γ in regulating centrosome licensing.
- Discovered a mechanism for 14-3-3/ligand complex formation/dissociation involving conserved acidic residues.
- Demonstrated that modulating 14-3-3γ-NPM1 interaction impacts centrosome duplication.
Related Concept Videos
02:25Centrosome Duplication
4.3K
The primary microtubule organizing center (MTOC) in animal cells is the centrosome. A centrosome has two cylindrical centrioles at its core. Each centriole consists of nine sets of three microtubules held together by proteins. The centrioles are positioned at right angles to each other and surrounded by a shapeless protein cloud called the pericentriolar matrix, or pericentriolar material (PCM).
To ensure that each daughter cell receives a centrosome after cell division, centrosome duplication...
To ensure that each daughter cell receives a centrosome after cell division, centrosome duplication...
4.3K
02:19The Spindle Assembly Checkpoint
3.4K
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
3.4K
02:17Separation of Sister Chromatids
4.0K
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
4.0K
02:02Meiosis II
48.3K
Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for meiosis II are similar to mitosis, except that meiosis II occurs in haploid cells, whereas mitosis occurs in diploid cells.
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
48.3K
02:57Attachment of Sister Chromatids
3.6K
As cells progress into mitosis, the nuclear envelope breaks down, and the condensed chromosomes are exposed to the array of bipolar microtubules of the mitotic spindle. The kinetochore, a large, disc-shaped protein complex, is present at the centromere region of the sister chromatids and acts as a binding site for the microtubules. Usually, the plus-end of a single microtubule is embedded within the kinetochore. However, some kinetochores first establish lateral contact with the side-wall...
3.6K
01:13Centrioles and Centrosomes
4.3K
Most animal cells comprise a pair of centrioles together called a centrosome. The cell duplicates its centrosome and contains two centrosomes side-by-side, which begin to move apart during the prophase. As the centrosomes migrate to two different sides of the cell, microtubules start extending from each centrosome toward the other end. The mitotic spindle is composed of the centrosomes and their emerging microtubules.
Near the end of the prophase, also called late prophase or...
Near the end of the prophase, also called late prophase or...
4.3K