Related Experiment Video
Updated: Jul 9, 2025
05:01
Author Spotlight: Developing Novel Anticancer Therapeutics Targeting the DNA Damage Response
Published on: June 14, 2024
1.3K
Melanoma-derived DNA polymerase theta variants exhibit altered DNA polymerase activity
Biorxiv : the Preprint Server for Biology
|November 28, 2023
Summary
DNA Polymerase θ (Pol θ) mutations found in melanoma alter DNA repair, reducing accuracy and efficiency. These Pol θ variants may aid cancer cell survival, metastasis, and drug resistance.
Area of Science:
- Molecular Biology
- Genetics
- Cancer Research
Background:
- DNA Polymerase θ (Pol θ) is crucial for DNA double-strand break repair via microhomology-mediated end joining (MMEJ).
- Pol θ is known for its high error rate but is essential for cell survival.
- Mutations in the POLQ gene are identified in human melanoma tumors.
Approach:
- Biochemical analysis of cancer-associated Pol θ variants.
- Comparison of variant polymerase activity, nucleotide selection, and polymerization rates against wild-type (WT) Pol θ.
Key Points:
- Cancer-associated Pol θ variants exhibit significantly reduced nucleotide incorporation efficiency (30-fold) and accuracy (70-fold) compared to WT Pol θ.
- Mutant Pol θ shows altered DNA polymerase activity, including increased incorrect nucleotide selection and slower polymerization.
- These findings suggest aberrant Pol θ has impaired DNA repair capabilities and may increase mutagenesis.
Conclusions:
- Aberrant Pol θ function in melanoma may impair DNA repair while potentially promoting increased mutagenesis.
- Cancer cells might exploit these Pol θ variants to enhance metastasis and drug resistance.
- Understanding Pol θ's role in cancer progression is critical for developing targeted therapies.
Related Concept Videos
02:10Translesion DNA Polymerases
10.0K
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
10.0K
01:31Proofreading
6.3K
Synthesis of new DNA molecules is carried out by the enzyme DNA polymerase, which adds nucleotides on the daughter strand complementary to the template DNA strand. DNA polymerase has a higher affinity to add the correct base and ensures fidelity during DNA replication. Furthermore, it exhibits proofreading activity during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.
Errors During Replication are Corrected by the DNA Polymerase...
Errors During Replication are Corrected by the DNA Polymerase...
6.3K
00:58Eukaryotic RNA Polymerases
24.2K
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...
24.2K
02:02DNA Topoisomerases
31.4K
Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
31.4K
01:38Nucleotide Excision Repair
3.5K
DNA Distortion and Damage
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
3.5K
02:37DNA Damage can Stall the Cell Cycle
9.2K
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
9.2K