Fip1--an essential component of the Saccharomyces cerevisiae polyadenylation machinery is phosophorylated by protein kinase CK2.
Since Fip1 is phosphoprotein we investigated whether it is a substrate for protein kinase CK2. According to the amino acid sequence Fip1 harbours twenty putative CK2 phosphorylation sites. Here we have report characterization of Fip1 as a substrate for both forms of CK2. Fip1 serves as a substrate for both the recombinant CK2alpha ' (Km 1.28 microM) and holoenzyme (Km 1.4 microM) but not for CK1. By MALDI-MS we identified the two serine residues at positions 73 and 77 as the possible in vitro phosphorylation sites. These data may help to elucidate the role of Fip1 in the mRNA 3'-OH polyadenylation process and the involvement of CK2 mediated phosphorylation in regulation of interactions and activity members of cleavage/polyadenylation factor (CPF) complex.
Department of Molecular Biology, Environmental Protection Institute, Catholic University of Lublin, Kraśnicka Av. 102, 20-718 Lublin, Poland.
Rafał
R
Zieliński
Ulf
U
Hellman
Konrad
K
Kubiński
Ryszard
R
Szyszka
D000595:Amino Acid Sequence; D047390:Casein Kinase II / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain / Q000235:genetics; D030562:Databases, Protein; D004591:Electrophoresis, Polyacrylamide Gel; D008954:Models, Biological; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011485:Protein Binding; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D039221:mRNA Cleavage and Polyadenylation Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C450579:FIP1 protein, S cerevisiae; D012333:RNA, Messenger; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; D047390:Casein Kinase II