UBE2T, the Fanconi anemia core complex, and FANCD2 are recruited independently to chromatin: a basis for the regulation of FANCD2 monoubiquitination.
The Fanconi anemia (FA) nuclear core complex and the E2 ubiquitin-conjugating enzyme UBE2T are required for the S phase and DNA damage-restricted monoubiquitination of FANCD2. This constitutes a key step in the FA tumor suppressor pathway, and much attention has been focused on the regulation at this point. Here, we address the importance of the assembly of the FA core complex and the subcellular localization of UBE2T in the regulation of FANCD2 monoubiquitination. We establish three points. First, the stable assembly of the FA core complex can be dissociated of its ability to function as an E3 ubiquitin ligase. Second, the actual E3 ligase activity is not determined by the assembly of the FA core complex but rather by its DNA damage-induced localization to chromatin. Finally, UBE2T and FANCD2 access this subcellular fraction independently of the FA core complex. FANCD2 monoubiquitination is therefore not regulated by multiprotein complex assembly but by the formation of an active E2/E3 holoenzyme on chromatin.
Alpi
Arno
A
Laboratory of Molecular Biology, Medical Research Council, Cambridge, United Kingdom.
Langevin
Frederic
F
Mosedale
Georgina
G
Machida
Yuichi J
YJ
Dutta
Anindya
A
Patel
Ketan J
KJ
D000818:Animals; D020134:Catalytic Domain; D002453:Cell Cycle; D002460:Cell Line; D002645:Chickens; D002843:Chromatin / Q000201:enzymology*; D004249:DNA Damage; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000378:metabolism*; D052240:Fanconi Anemia Complementation Group L Protein / Q000378:metabolism; D006801:Humans; D011485:Protein Binding; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism*; D054875:Ubiquitination
D002843:Chromatin; D052236:Fanconi Anemia Complementation Group D2 Protein; D044763:Ubiquitin-Conjugating Enzymes; D052240:Fanconi Anemia Complementation Group L Protein