DNA fragmentation factor 45kDa, middle domain (IPR015121)

Short name: DNA_fragmentation_mid_dom

Overlapping homologous superfamilies


Domain relationships



One of the hallmarks of the terminal stages of apoptosis is internucleosomal DNA breakdown. DNA fragmentation factor (DFF) and endonuclease G (Endo G) are responsible for this process. DFF exists in the nucleus as a heterodimer composed of a 45kDa chaperone and inhibitor subunit (DFF45, also called ICAD-L) and a 40kDa latent nuclease subunit (DFF40/CAD). Apoptotic activation of caspase-3 or -7 results in the cleavage of DFF45 and release of active DFF40 nuclease, which forms homo-oligomers. DFF40's nuclease activity is further activated by proteins such as histone H1, HMGB1/2, and topoisomerase II [PMID: 15723341].

This entry identifies the middle section of DNA fragmentation factor 45 and spans part of the C-terminal four helical domain.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.