Related Experiment Video
Updated: May 15, 2026
11:40
Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy
Published on: June 25, 2013
On BLM helicase in recombination-mediated telomere maintenance
1Division of Molecular Diagnosis and Research, Booali Medical Laboratory, Qom, Iran. sarallahrezazadeh@yahoo.com
Molecular Biology Reports
|December 27, 2012
Summary
Bloom syndrome (BS) is a rare genetic disorder linked to the BLM gene. The BLM helicase may play a crucial role in telomere maintenance through alternative lengthening of telomeres (ALT) in cancer cells.
Area of Science:
- Genetics
- Molecular Biology
- Cancer Research
Background:
- Bloom syndrome (BS) is a rare autosomal recessive disorder.
- BS patients exhibit genomic instability, predisposition to cancer, and premature aging.
- The syndrome is characterized by a hyper-recombination phenotype, including elevated sister chromatid exchange rates.
Purpose of the Study:
- To explore the potential role of the BLM helicase in telomere maintenance.
- To investigate the BLM helicase's function in alternative lengthening of telomeres (ALT), a telomerase-independent mechanism.
- To understand the implications of BLM in cancer and aging.
Main Methods:
- Review of RecQ helicase features.
- Survey of evidence implicating BLM in recombination-mediated telomere elongation.
- Analysis of BLM localization in ALT-associated PML nuclear bodies.
- Examination of BLM protein interactions with telomere-specific proteins.
Main Results:
- The BLM gene encodes a RecQ-like helicase involved in DNA repair pathways.
- Evidence suggests BLM helicase may be crucial for telomerase-independent telomere elongation (ALT).
- BLM's presence in ALT-associated PML nuclear bodies supports its role in ALT.
Conclusions:
- The BLM helicase is a key player in maintaining genomic stability and may be vital for ALT.
- Understanding BLM's function in telomere biology could offer insights into cancer development and aging.
- Further research into BLM's role in ALT is warranted.
Related Concept Videos
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
02:53Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
02:41Telomeres and Telomerase
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.
02:41Telomeres and Telomerase
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.
02:37Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...