Phosphorylation of Fanconi anemia protein, FANCA, is regulated by Akt kinase.
Phosphorylation of the Fanconi anemia complementation group A (FANCA) protein is thought to be important for the function of the FA pathway. However, the kinase for FANCA (so-called FANCA-PK) remains to be identified. FANCA has a consensus sequence for Akt kinase near serine 1149 (Ser1149), suggesting that Akt can phosphorylate FANCA. We performed in vitro kinase assays using as substrate either a GST-fusion wild-type (WT) FANCA fragment or a GST-fusion FANCA fragment containing a mutation from serine to alanine at 1149 (FANCA-S1149A). These experiments confirmed that FANCA is phosphorylated at Ser 1149, in vitro. However, (32)P-orthophosphate labeling experiments revealed that FANCA-S1149A was more efficiently phosphorylated than WT-FANCA. Furthermore, phosphorylation of wild-type FANCA was blocked by coexpression of a constitutively active (CA)-Akt and enhanced by a dominant-negative (DN) Akt. Our results suggest that Akt is a negative regulator of FANCA phosphorylation.
Otsuki
Tetsuya
T
Department of Hematology, Center for Molecular Medicine, Jichi Medical School, Yakushiji 3311-1, Minamikawachi, Kawachi, Tochigi, 329-0498, Japan.
Nagashima
Takahiro
T
Komatsu
Norio
N
Kirito
Keita
K
Furukawa
Yusuke
Y
Kobayashi Si
Shin-ichi
S
Liu
Johnson M
JM
Ozawa
Keiya
K
D000595:Amino Acid Sequence; D002460:Cell Line; D016384:Consensus Sequence; D004268:DNA-Binding Proteins; D052217:Fanconi Anemia Complementation Group A Protein; D005816:Genetic Complementation Test; D006801:Humans; D010766:Phosphorylation; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D051057:Proto-Oncogene Proteins c-akt
D004268:DNA-Binding Proteins; C498471:FANCA protein, human; D052217:Fanconi Anemia Complementation Group A Protein; D011506:Proteins; D011518:Proto-Oncogene Proteins; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt