PAP Associated Domain Containing Protein 5 (PAPD5)

Campothecin, a plant alkaloid derived from a Chinese tree, is an antitumor agent that causes DNA damage by targeting DNA topoisomerase I (TOP1). Yeast cells lacking TOP1 are completely resistant to killing by the drug. TOP1 functions together with TRF4 in the process of mitotic chromosome condensation. Like yeast MCD1 and SCC1, TRF4 is required for sister chromatid cohesion. Walowsky et al. (1999) found that yeast with mutant TRF4 are hypersensitive to killing by campothecin and to methyl methanesulfonate but not ultraviolet irradiation.By EST database searching for human sequences homologous to yeast TRF4, Walowsky et al. (1999) identified cDNAs encoding TRF4-1 and TRF4-2. The deduced 381-amino acid TRF4-2 protein shares 65% sequence identity with TRF4-1.