Protein kinase CK2 phosphorylates the Fas-associated factor FAF1 in vivo and influences its transport into the nucleus.
We previously identified the Fas-associated factor FAF1 as an in vitro substrate of protein kinase CK2 and determined Ser289 and Ser291 as phosphorylation sites. Here we demonstrate that these two serine residues are the only sites phosphorylated by CK2 in vitro, and that at least one site is phosphorylated in vivo. Furthermore, we analyzed putative physiological functions of FAF1 phosphorylation. The ability of FAF1 to potentiate Fas-induced apoptosis is not influenced by the FAF1 phosphorylation status; however, the nuclear import of a phosphorylation-deficient FAF1 mutant was delayed in comparison to wild-type FAF1.
Olsen
Birgitte B
BB
Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
Jessen
Vibeke
V
Højrup
Peter
P
Issinger
Olaf-Georg
OG
Boldyreff
Brigitte
B
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D047390:Casein Kinase II; D002467:Cell Nucleus / Q000201:enzymology; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins; C490780:FAF1 protein, human; D012694:Serine; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases