Characterization, expression and complex formation of the murine Fanconi anaemia gene product Fancg.
BACKGROUND
Fanconi anaemia (FA) is an autosomal recessive chromosomal instability disorder. Six distinct FA disease genes have been identified, the products of which function in an integrated pathway that is thought to support a nuclear caretaker function. Comparison of FA gene characteristics in different species may help to unravel the molecular function of the FA pathway.


RESULTS
We have cloned the murine homologue of the Fanconi anaemia complementation group G gene, FANCG/XRCC9. The murine Fancg protein shows an 83% similarity to the human protein sequence, and has a predicted molecular weight of 68.5 kDa. Expression of mouse Fancg in human FA-G lymphoblasts fully corrects their cross-linker hypersensitivity. At mRNA and protein levels we detected the co-expression of Fancg and Fanca in murine tissues. In addition, mouse Fancg and Fanca proteins co-purify by immunoprecipitation. Upon transfection into Fanca-deficient mouse embryonic fibroblasts EGFP-Fancg chimeric protein was detectable in the nucleus.


CONCLUSIONS
We identified a murine cDNA, Fancg, which cross-complements the cellular defect of human FA-G cells and thus represents a true homologue of human FANCG. Spleen, thymus and testis showed the highest Fancg expression levels. Although Fancg and Fanca are able to form a complex, this interaction is not required for Fancg to accumulate in the nuclear compartment.
van de Vrugt
Henri J
HJ
Department of Clinical Genetics and Human Genetics, VU University medical centre, Van der Boechorststraat 7, NL-1081 BT Amsterdam, the Netherlands.
Koomen
Mireille
M
Berns
Mariska A D
MA
de Vries
Yne
Y
Rooimans
Martin A
MA
van der Weel
Laura
L
Blom
Eric
E
de Groot
Jan
J
Schepers
Rik J
RJ
Stone
Stacie
S
Hoatlin
Maureen E
ME
Cheng
Ngan Ching
NC
Joenje
Hans
H
Arwert
Fré
F
D000595:Amino Acid Sequence; D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005199:Fanconi Anemia / Q000235:genetics* / Q000378:metabolism*; D052217:Fanconi Anemia Complementation Group A Protein; D052241:Fanconi Anemia Complementation Group G Protein; D005347:Fibroblasts / Q000378:metabolism; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D051379:Mice; D008969:Molecular Sequence Data; D011506:Proteins / Q000378:metabolism; D012333:RNA, Messenger; D016415:Sequence Alignment
D004268:DNA-Binding Proteins; C120277:Fanca protein, mouse; C499910:Fancg protein, mouse; D052217:Fanconi Anemia Complementation Group A Protein; D052241:Fanconi Anemia Complementation Group G Protein; D008164:Luminescent Proteins; D011506:Proteins; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins