Related Experiment Video

Updated: Apr 25, 2026

Immunofluorescence Analysis of Endogenous and Exogenous Centromere-kinetochore Proteins
05:35

Immunofluorescence Analysis of Endogenous and Exogenous Centromere-kinetochore Proteins

Published on: March 3, 2016

15.0K

Localization of MLH3 at the centrosomes

Lennart M Roesner1, Christian Mielke2, Silke Faehnrich3

  • 1Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Department of Human and Animal Cell Lines, Braunschweig 38124, Germany. roesner.lennart@mh-hannover.de.

International Journal of Molecular Sciences
|August 14, 2014
PubMed

Insights

MLH3, a DNA repair protein, accumulates at centrosomes during the cell cycle. Its high mobility suggests a role in regulating centrosome numbers alongside other DNA repair proteins.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Genetics

Background:

  • Mutations in DNA mismatch repair (MMR) genes are linked to hereditary nonpolyposis colorectal cancer (HNPCC).
  • The MLH1 protein forms heterodimers with PMS2, PMS1, and MLH3, creating MutLα, MutLβ, and MutLγ complexes.
  • Previous work established stable expression of GFP-linked MLH3 in human cell lines.

Purpose of the Study:

  • To investigate the cellular localization and dynamics of MLH3 during the cell cycle.
  • To explore the potential role of MLH3 in DNA repair and centrosome regulation.

Main Methods:

  • Stable expression of GFP-linked MLH3 in human cell lines.
  • Live cell imaging with confocal microscopy to monitor MLH3 localization.
  • Fluorescence recovery after photobleaching (FRAP) to assess MLH3 mobility at centrosomes.

Main Results:

  • MLH3 was observed to accumulate at the centrosomes during the cell cycle.
  • FRAP analysis indicated high mobility and rapid exchange rates of MLH3 at centrosomes.
  • These dynamics are comparable to other known DNA repair proteins.

Conclusions:

  • MLH3 exhibits dynamic behavior at centrosomes, suggesting a functional role in this cellular compartment.
  • MLH3 may collaborate with other DNA repair proteins to influence centrosome number control.
  • Further research is warranted to elucidate the precise mechanisms of MLH3 in DNA repair and cell cycle regulation.

More Related Videos

Quantitative Immunofluorescence Assay to Measure the Variation in Protein Levels at Centrosomes09:39

Quantitative Immunofluorescence Assay to Measure the Variation in Protein Levels at Centrosomes

Published on: December 20, 2014

14.8K
Robust 3D DNA FISH Using Directly Labeled Probes12:16

Robust 3D DNA FISH Using Directly Labeled Probes

Published on: August 15, 2013

37.4K

Related Concept Videos

Centrosome Duplication02:25

Centrosome Duplication

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...
3.7K
Centrosome Duplication02:25

Centrosome Duplication

2.5K
Histone Variants at the Centromere02:30

Histone Variants at the Centromere

Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3...
4.0K
Centrioles and Centrosomes01:13

Centrioles and Centrosomes

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...
6.8K
The Mitotic Spindle02:27

The Mitotic Spindle

The mitotic spindle—or spindle apparatus—is a eukaryotic, cytoskeletal structure made up of long protein fibers called microtubules. Formed during cell division, the spindle separates sister chromatids and moves them to opposite ends of a parental cell, where the now individual chromosomes are distributed to two daughter cell nuclei.
The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures...
7.1K
Attachment of Sister Chromatids02:57

Attachment of Sister Chromatids

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...
3.1K