Functional domains involved in the interaction between Orc1 and transcriptional repressor AlF-C that bind to an origin/promoter of the rat aldolase B gene.
The promoter of the rat aldolase B (AldB) gene functions in vivo as an origin of DNA replication in the cells in which transcription of the gene is repressed. Previously, we identified two closely related DNA-binding proteins, AlF-C1 and AlF-C2, which repressed the AldB gene promoter. We also reported that the binding site of these proteins, site C, is one of the required DNA elements of the AldB gene origin/promoter for autonomously replicating activity in transfected cells. In the present study, we show that AlF-C1 and AlF-C2 bind directly to Orc1, a subunit of the origin recognition complex (ORC). Deletion analyses revealed a functional domain in AlF-C2 for binding to Orc1, which is located separately from the DNA-binding domain. In addition, we found a novel protein-interacting domain in Orc1 required for the binding of AlF-C2, which was conserved in human, mouse and Chinese hamster, but not in Drosophila, frog and yeast. Thus, it is assumed that in mammalian cells, sequence- specific DNA-binding proteins are involved in recruiting ORC to regulate replication initiation and/or transcription repression.
Saitoh
Yasushi
Y
Cryobiosystem Research Center, Faculty of Agriculture, Iwate University, 3-18-8, Ueda, Morioka, Iwate 020-8550, Japan.
Miyagi
Satoru
S
Ariga
Hiroyoshi
H
Tsutsumi
Ken-ichi
K
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D018797:Cell Cycle Proteins; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D005634:Fructose-Bisphosphate Aldolase / Q000235:genetics*; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism; D051738:Origin Recognition Complex; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D051381:Rats; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism*; D012261:Ribonucleoproteins; D016415:Sequence Alignment; D014157:Transcription Factors; D014158:Transcription, Genetic
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; C121363:Hnrnpab protein, rat; D009687:Nuclear Proteins; C497228:Orc1 protein, mouse; D051738:Origin Recognition Complex; D012097:Repressor Proteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; C077048:Hnrnpab protein, mouse; D005634:Fructose-Bisphosphate Aldolase