FANCJ protein is important for the stability of FANCD2/FANCI proteins and protects them from proteasome and caspase-3 dependent degradation.
Fanconi anemia (FA) is a rare genome instability syndrome with progressive bone marrow failure and cancer susceptibility. FANCJ is one of 17 genes mutated in FA-patients, comprises a DNA helicase that is vital for properly maintaining genomic stability and is known to function in the FA-BRCA DNA repair pathway. While exact role(s) of FANCJ in this repair process is yet to be determined, it is known to interact with primary effector FANCD2. However, FANCJ is not required for FANCD2 activation but is important for its ability to fully respond to DNA damage. In this report, we determined that transient depletion of FANCJ adversely affects stability of FANCD2 and its co-regulator FANCI in multiple cell lines. Loss of FANCJ does not significantly alter cell cycle progression or FANCD2 transcription. However, in the absence of FANCJ, the majority of FANCD2 is degraded by both the proteasome and Caspase-3 dependent mechanism. FANCJ is capable of complexing with and stabilizing FANCD2 even in the absence of a functional helicase domain. Furthermore, our data demonstrate that FANCJ is important for FANCD2 stability and proper activation of DNA damage responses to replication blocks induced by hydroxyurea.
Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA.
David W
DW
Clark
Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA.
Kaushlendra
K
Tripathi
Department of Clinical Genetics, Section Oncogenetics, VU University Medical Center, Amsterdam, The Netherlands.
Josephine C
JC
Dorsman
Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA.
Komaraiah
K
Palle
D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism*; D045744:Cell Line, Tumor; D004249:DNA Damage; D004260:DNA Repair; D004795:Enzyme Stability; D005199:Fanconi Anemia / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000235:genetics / Q000378:metabolism*; D051856:Fanconi Anemia Complementation Group Proteins / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D061988:Proteasome Inhibitors / Q000494:pharmacology; D011485:Protein Binding; D059748:Proteolysis; D034622:RNA Interference; D013997:Time Factors; D014162:Transfection; D054875:Ubiquitination
C102108:BACH1 protein, human; D050976:Basic-Leucine Zipper Transcription Factors; C499905:FANCD2 protein, human; C519921:FANCI protein, human; D052236:Fanconi Anemia Complementation Group D2 Protein; D051856:Fanconi Anemia Complementation Group Proteins; D061988:Proteasome Inhibitors; C505407:CASP3 protein, human; D053148:Caspase 3; D046988:Proteasome Endopeptidase Complex; D006918:Hydroxyurea
FANCD2; FANCJ; Fanconi anemia; caspase-3; proteasome