Role of CK2-dependent phosphorylation of Ifh1 and Crf1 in transcriptional regulation of ribosomal protein genes in Saccharomyces cerevisiae.
In Saccharomyces cerevisiae, Fhl1 is involved in the regulation of ribosomal protein (RP) genes through interaction with either its coactivator Ifh1 or corepressor Crf1, depending on nutrient conditions. Interaction of Fhl1 with Ifh1 or Crf1 is achieved through a forkhead-associated (FHA) domain of Fhl1, which binds to forkhead-binding (FHB) domains of Ifh1 and Crf1. Here, we demonstrate that CK2-dependent phosphorylation of T681 and T348 residues, located in the FHB domains of Ifh1 and Crf1, respectively, provides binding sites for the FHA domain of Fhl1. Cells expressing Ifh1(T681A) mutant showed reduced association of Ifh1 at the RP gene promoters and decreased levels of RP gene transcripts, thereby reducing the growth rate. On the other hand, cells expressing Crf1(T348A) showed a defect in repressing RP gene transcription upon inhibition of target of rapamycin complex 1 (TORC1) by rapamycin treatment. Taken together, these findings suggest the mechanisms by which CK2-dependent recruitment of Ifh1 and Crf1 at the RP gene promoters governs the transcription of RP genes.
School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Myung Sup
MS
Kim
School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea. Electronic address: hahnjs@snu.ac.kr.
Ji-Sook
JS
Hahn
D000595:Amino Acid Sequence; D001665:Binding Sites; D047390:Casein Kinase II / Q000235:genetics* / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D009154:Mutation; D010766:Phosphorylation / Q000187:drug effects; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D000072417:Protein Domains; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D020123:Sirolimus / Q000494:pharmacology; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
C495982:CRF1 protein, S cerevisiae; C495776:FHL1 protein, S cerevisiae; D051858:Forkhead Transcription Factors; C094046:IFH1 protein, S cerevisiae; D012097:Repressor Proteins; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C561842:TORC1 protein complex, S cerevisiae; D015534:Trans-Activators; D014157:Transcription Factors; D047390:Casein Kinase II; D020123:Sirolimus
CK2; Crf1; Fhl1; Ifh1; Ribosomal protein gene; Saccharomyces cerevisiae