Noc3p, a bHLH protein, plays an integral role in the initiation of DNA replication in budding yeast.
Initiation of eukaryotic DNA replication requires many proteins that interact with one another and with replicators. Using a yeast genetic screen, we have identified Noc3p (nucleolar complex-associated protein) as a novel replication-initiation protein. Noc3p interacts with MCM proteins and ORC and binds to chromatin and replicators throughout the cell cycle. It functions as a critical link between ORC and other initiation proteins to effect chromatin association of Cdc6p and MCM proteins for the establishment and maintenance of prereplication complexes. Noc3p is highly conserved in eukaryotes and is the first identified bHLH (basic helix-loop-helix) protein required for replication initiation. As Noc3p is also required for pre-rRNA processing, Noc3p is a multifunctional protein that plays essential roles in two vital cellular processes.
Zhang
Yuexuan
Y
Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
Yu
Zhiling
Z
Fu
Xinrong
X
Liang
Chun
C
D015153:Blotting, Western; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone; D015825:Chromosomes, Fungal / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005434:Flow Cytometry; D005656:Fungal Proteins / Q000378:metabolism; D018257:Helix-Loop-Helix Motifs; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D029543:Nucleocytoplasmic Transport Proteins; D051738:Origin Recognition Complex; D011485:Protein Binding; D018741:Replication Origin / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins; D013489:Suppression, Genetic / Q000235:genetics
C066503:CDC6 protein, S cerevisiae; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C069200:MCM5 protein, S cerevisiae; C429648:NOC3 protein, S cerevisiae; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D051738:Origin Recognition Complex; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C085711:mcm5 protein, S pombe; C069199:MCM2 protein, S cerevisiae