High impact information on DEF1

• The phenotypes of cells lacking DEF1 are consistent with a role for this factor in the DNA damage response, but Def1 is not required for TCR [1].
• A Rad26-Def1 complex coordinates repair and RNA pol II proteolysis in response to DNA damage [1].
• Rather, def1 cells are compromised for transcript elongation, and are unable to degrade RNA polymerase II (RNAPII) in response to DNA damage [1].
• A combination of DEF1 null mutation with deletion of EST2 or EST3 resulted in an accelerated senescence phenotype, suggesting that Def1p is not involved in the telomerase recruitment pathway [2].
• In def1 mutants, telomeres were approximately 200-bp shorter than that in wild-type cells [2].

Anatomical context of DEF1

• DEF1 is also required for the stable maintenance of mitochondrial DNA, and the telomere shortening phenotype seen in def1 cells is not a secondary consequence of the mitochondrion defect [2].

Other interactions of DEF1

• In yeast, this requires the DEF1 gene, the product of which forms a complex with the transcription-coupling repair factor, Rad26 [3].

References