Three eukaryote-like Orc1/Cdc6 proteins functionally interact and mutually regulate their activities of binding to the replication origin in the hyperthermophilic archaeon Sulfolobus solfataricus P2.
The crenarchaeon Sulfolobus solfataricus has the potential to be a powerful model system to understand the central mechanism of eukaryotic DNA replication because it contains three active origins of replication and three eukaryote-like Orc1/Cdc6 proteins. However, it is not known whether these SsoCdc6 proteins can functionally interact and collectively contribute to DNA replication initiation. In the current work, we found that SsoCdc6-1 stimulates DNA-binding activities of SsoCdc6-3. In contrast, SsoCdc6-3 inhibits those of both SsoCdc6-1 and SsoCdc6-2. These regulatory functions are differentially affected by the C-terminal domains of these SsoCdc6 proteins. These data, in conjunction with studies on physical interactions between these replication initiators by bacterial two-hybrid and pull-down/Western blot assays, lead us to propose the possibility that multiple SsoCdc6 proteins might coordinately regulate DNA replication in the archaeon species. This is the first report on the functional interaction among the archaeal multiple Cdc6 proteins to regulate DNA replication.
Wang
Jun
J
National Key Laboratory of Agricultural Microbiology, Center for Proteomics Research, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Jiang
Pei-Xia
PX
Feng
Hui
H
Feng
Ying
Y
He
Zheng-Guo
ZG
D004261:DNA Replication / Q000502:physiology*; D051738:Origin Recognition Complex / Q000145:classification / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D020033:Protein Isoforms / Q000378:metabolism; D018741:Replication Origin / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins / Q000145:classification / Q000378:metabolism*; D013045:Species Specificity; D048229:Sulfolobus solfataricus / Q000502:physiology*