translesionsynteesiä

Translesion synthesis (TLS) is a DNA repair mechanism that allows cells to replicate DNA even in the presence of DNA damage. When DNA polymerase encounters a damaged base during replication, it can stall. TLS polymerases are specialized enzymes that can bypass these lesions, inserting a nucleotide opposite the damaged base. This process is error-prone, meaning it can lead to mutations, but it is crucial for preventing complete replication fork collapse and cell death.

There are multiple TLS polymerases in cells, each with different substrate specificities and error rates. Some TLS polymerases are more promiscuous and can insert almost any nucleotide opposite a lesion, while others are more selective. The choice of which TLS polymerase is recruited to a lesion is influenced by various factors, including the type of damage and the cellular context.

While TLS is essential for survival, its mutagenic nature means it plays a role in processes like cancer development and drug resistance. However, it is also involved in some adaptive responses. Understanding TLS is important for developing strategies to target cancer cells or enhance the efficacy of certain therapies.