Methotrexate hydrate, DHFR inhibitor

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

TDP1 short for Tyrosyl-DNA Phosphodiesterase 1 is an enzyme involved in the repair of DNA damage. Also known as SCAN1 protein this enzyme has a mass of approximately 60 kDa and is expressed in a variety of tissues with higher levels seen in the brain and heart. It plays a mechanical role by hydrolyzing the phosphodiester bond between a DNA 3'-phosphate and a tyrosine residue an important step in resolving topoisomerase I-DNA crosslinks during the repair of stalled replication forks.

Biological function summary

TDP1 contributes significantly to the maintenance of genomic stability. It functions primarily as a DNA repair enzyme acting independently rather than as part of a protein complex. TDP1's ability to cleave phosphotyrosyl bonds makes it integral to processes that safeguard against DNA strand breaks induced by oxidative stress or other exogenous factors. Though not part of a complex its function is supported by the interaction with proteins like DNA polymerase which aids in the subsequent steps of DNA repair synthesis.

Pathways

TDP1 is involved in the DNA damage response and repair pathways. It collaborates heavily with the Base Excision Repair (BER) and the Single-Strand Break Repair (SSBR) pathways. TDP1 works alongside proteins like PARP1 facilitating the repair of single-strand DNA breaks which is critical for cell survival and prevention of mutations. Aphidicolin a known inhibitor of DNA polymerase can affect DNA synthesis steps that follow TDP1 activity indicating how interconnected these pathways are.

TDP1 has notable associations with certain neurodegenerative diseases and cancer. Mutations or dysregulation in TDP1 have been implicated in the autosomal recessive disorder known as Spinocerebellar Ataxia with Axonal Neuropathy (SCAN1). Additionally due to its role in DNA repair TDP1 may influence cancer progression as cells with impaired DNA repair capabilities accumulate mutations that could lead to tumorigenesis. The interaction with methotrexate a chemotherapeutic agent can also affect cancer treatment outcomes given methotrexate's influence on folate metabolism and DNA synthesis.