A coordinated temporal interplay of nucleosome reorganization factor, sister chromatin cohesion factor, and DNA polymerase alpha facilitates DNA replication.
DNA replication depends critically upon chromatin structure. Little is known about how the replication complex overcomes the nucleosome packages in chromatin during DNA replication. To address this question, we investigate factors that interact in vivo with the principal initiation DNA polymerase, DNA polymerase alpha (Polalpha). The catalytic subunit of budding yeast Polalpha (Pol1p) has been shown to associate in vitro with the Spt16p-Pob3p complex, a component of the nucleosome reorganization system required for both replication and transcription, and with a sister chromatid cohesion factor, Ctf4p. Here, we show that an N-terminal region of Polalpha (Pol1p) that is evolutionarily conserved among different species interacts with Spt16p-Pob3p and Ctf4p in vivo. A mutation in a glycine residue in this N-terminal region of POL1 compromises the ability of Pol1p to associate with Spt16p and alters the temporal ordered association of Ctf4p with Pol1p. The compromised association between the chromatin-reorganizing factor Spt16p and the initiating DNA polymerase Pol1p delays the Pol1p assembling onto and disassembling from the late-replicating origins and causes a slowdown of S-phase progression. Our results thus suggest that a coordinated temporal and spatial interplay between the conserved N-terminal region of the Polalpha protein and factors that are involved in reorganization of nucleosomes and promoting establishment of sister chromatin cohesion is required to facilitate S-phase progression.
Zhou
Yanjiao
Y
Department of Pathology, Edwards Building, Room R270, Stanford University Medical Center, 300 Pasteur Dr., Stanford, CA 94305-5324, USA.
Wang
Teresa S-F
TS
D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D004256:DNA Polymerase I / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D015966:Gene Expression Regulation, Fungal; D042822:Genomic Instability; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009707:Nucleosomes / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D016196:S Phase; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D013696:Temperature; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D035602:Transcriptional Elongation Factors
C078338:CTF4 protein, S cerevisiae; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D009707:Nucleosomes; C106768:POB3 protein, S cerevisiae; D011506:Proteins; C071238:SPT16 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D004256:DNA Polymerase I