FAN1 Acts with FANCI-FANCD2 to Promote DNA Interstrand Cross-Link Repair

Abstract

Fanconi Anemia Protein in DNA Binding Fanconi anemia patients suffer a number of symptoms, including increased sensitivity to chemicals that cross-link DNA strands of the double helix together. Such aberrations can lead to genome instability. Mutations in 13 different genes implicated in repairing damaged DNA are known to be involved in the disease. Liu et al. (p. 693 , published online 29 July) have identified a new factor, FAN1 (Fanconi anemia–associated nuclease 1), which they find to be associated with a complex of two of the FANC proteins, FANCI and FANCD2 (the ID complex). The mono-ubiquitylated ID complex locates to sites of DNA damage to which it recruits FAN1, a mono-ubiquitin–binding protein. FAN1 has a DNA branch–specific nuclease activity that is required for the removal and subsequent repair of the interstrand DNA cross-links.