scholarly journals Subnuclear distribution of the largest subunit of the human origin recognition complex during the cell cycle

2004 ◽  
Vol 117 (22) ◽  
pp. 5221-5231 ◽  
Author(s):  
M. R. Lidonnici
Keyword(s):  
Cell Cycle ◽  
Origin Recognition Complex ◽  
Human Origin ◽  
Origin Recognition

scholarly journals Investigation of the Interaction of Human Origin Recognition Complex Subunit 1 with G-Quadruplex DNAs of Human c-myc Promoter and Telomere Regions

2021 ◽  
Vol 22 (7) ◽  
pp. 3481
Author(s):  
Afaf Eladl ◽  
Yudai Yamaoki ◽  
Shoko Hoshina ◽  
Haruka Horinouchi ◽  
Keiko Kondo ◽  
...  
Keyword(s):  
Fluorescence Anisotropy ◽  
Binding Sites ◽  
Replication Origin ◽  
Origin Recognition Complex ◽  
Chemical Shift Perturbation ◽  
Human Origin ◽  
Replication Origins ◽  
Genome Wide ◽  
G Quadruplex ◽  
Origin Recognition

Origin recognition complex (ORC) binds to replication origins in eukaryotic DNAs and plays an important role in replication. Although yeast ORC is known to sequence-specifically bind to a replication origin, how human ORC recognizes a replication origin remains unknown. Previous genome-wide studies revealed that guanine (G)-rich sequences, potentially forming G-quadruplex (G4) structures, are present in most replication origins in human cells. We previously suggested that the region comprising residues 413–511 of human ORC subunit 1, hORC1413–511, binds preferentially to G-rich DNAs, which form a G4 structure in the absence of hORC1413–511. Here, we investigated the interaction of hORC1413-511 with various G-rich DNAs derived from human c-myc promoter and telomere regions. Fluorescence anisotropy revealed that hORC1413–511 binds preferentially to DNAs that have G4 structures over ones having double-stranded structures. Importantly, circular dichroism (CD) and nuclear magnetic resonance (NMR) showed that those G-rich DNAs retain the G4 structures even after binding with hORC1413–511. NMR chemical shift perturbation analyses revealed that the external G-tetrad planes of the G4 structures are the primary binding sites for hORC1413–511. The present study suggests that human ORC1 may recognize replication origins through the G4 structure.

scholarly journals Control of DNA Rereplication via Cdc2 Phosphorylation Sites in the Origin Recognition Complex

2001 ◽  
Vol 21 (17) ◽  
pp. 5767-5777 ◽  
Author(s):  
Amit Vas ◽  
Winnie Mok ◽  
Janet Leatherwood
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Origin Recognition Complex ◽  
Safety Net ◽  
Replication Initiation ◽  
Initiation Factor ◽  
Phosphorylation Sites ◽  
Cdc2 Kinase ◽  
Origin Recognition ◽  
Dna Rereplication

ABSTRACT Cdc2 kinase is a master regulator of cell cycle progression in the fission yeast Schizosaccharomyces pombe. Our data indicate that Cdc2 phosphorylates replication factor Orp2, a subunit of the origin recognition complex (ORC). Cdc2 phosphorylation of Orp2 appears to be one of multiple mechanisms by which Cdc2 prevents DNA rereplication in a single cell cycle. Cdc2 phosphorylation of Orp2 is not required for Cdc2 to activate DNA replication initiation. Phosphorylation of Orp2 appears first in S phase and becomes maximal in G2 and M when Cdc2 kinase activity is required to prevent reinitiation of DNA replication. A mutant lacking Cdc2 phosphorylation sites in Orp2 (orp2-T4A) allowed greater rereplication of DNA than congenic orp2 wild-type strains when the limiting replication initiation factor Cdc18 was deregulated. Thus, Cdc2 phosphorylation of Orp2 may be redundant with regulation of Cdc18 for preventing reinitiation of DNA synthesis. Since Cdc2 phosphorylation sites are present in Orp2 (also known as Orc2) from yeasts to metazoans, we propose that cell cycle-regulated phosphorylation of the ORC provides a safety net to prevent DNA rereplication and resulting genetic instability.

scholarly journals Subsets of Human Origin Recognition Complex (ORC) Subunits Are Expressed in Non-proliferating Cells and Associate with Non-ORC Proteins

2000 ◽  
Vol 275 (45) ◽  
pp. 35233-35241 ◽  
Author(s):  
Kelly C. Thome ◽  
Suman K. Dhar ◽  
David G. Quintana ◽  
Laurie Delmolino ◽  
Aliakbar Shahsafaei ◽  
...  
Keyword(s):  
Origin Recognition Complex ◽  
Human Origin ◽  
Proliferating Cells ◽  
Origin Recognition

scholarly journals Human Origin Recognition Complex Binds Preferentially to G-quadruplex-preferable RNA and Single-stranded DNA

2013 ◽  
Vol 288 (42) ◽  
pp. 30161-30171 ◽  
Author(s):  
Shoko Hoshina ◽  
Kei Yura ◽  
Honami Teranishi ◽  
Noriko Kiyasu ◽  
Ayumi Tominaga ◽  
...  
Keyword(s):  
Origin Recognition Complex ◽  
Human Origin ◽  
Single Stranded Dna ◽  
G Quadruplex ◽  
Origin Recognition

scholarly journals Assembly of the Human Origin Recognition Complex Occurs through Independent Nuclear Localization of Its Components

2011 ◽  
Vol 286 (27) ◽  
pp. 23831-23841 ◽  
Author(s):  
Soma Ghosh ◽  
Alex P. Vassilev ◽  
Junmei Zhang ◽  
Yingming Zhao ◽  
Melvin L. DePamphilis
Keyword(s):  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Origin Recognition Complex ◽  
Genome Duplication ◽  
Cyclin Dependent Kinase ◽  
Human Origin ◽  
Cell Extracts ◽  
Localization Signal ◽  
Origin Recognition

Initiation of eukaryotic genome duplication begins when a six-subunit origin recognition complex (ORC) binds to DNA. However, the mechanism by which this occurs in vivo and the roles played by individual subunits appear to differ significantly among organisms. Previous studies identified a soluble human ORC(2–5) complex in the nucleus, an ORC(1–5) complex bound to chromatin, and an Orc6 protein that binds weakly, if at all, to other ORC subunits. Here we show that stable ORC(1–6) complexes also can be purified from human cell extracts and that Orc6 and Orc1 each contain a single nuclear localization signal that is essential for nuclear localization but not for ORC assembly. The Orc6 nuclear localization signal, which is essential for Orc6 function, is facilitated by phosphorylation at its cyclin-dependent kinase consensus site and by association with Kpna6/1, nuclear transport proteins that did not co-purify with other ORC subunits. These and other results support a model in which Orc6, Orc1, and ORC(2–5) are transported independently to the nucleus where they can either assemble into ORC(1–6) or function individually.

scholarly journals Studies of the properties of human origin recognition complex and its Walker A motif mutants

2004 ◽  
Vol 102 (1) ◽  
pp. 69-74 ◽  
Author(s):  
J. Giordano-Coltart ◽  
C. Y. Ying ◽  
J. Gautier ◽  
J. Hurwitz
Keyword(s):  
Origin Recognition Complex ◽  
Human Origin ◽  
Origin Recognition

scholarly journals Human origin recognition complex is essential for HP1 binding to chromatin and heterochromatin organization

2010 ◽  
Vol 107 (34) ◽  
pp. 15093-15098 ◽  
Author(s):  
S. G. Prasanth ◽  
Z. Shen ◽  
K. V. Prasanth ◽  
B. Stillman
Keyword(s):  
Origin Recognition Complex ◽  
Human Origin ◽  
Origin Recognition

scholarly journals Phosphorylation of ORC2 Protein Dissociates Origin Recognition Complex from Chromatin and Replication Origins

2012 ◽  
Vol 287 (15) ◽  
pp. 11891-11898 ◽  
Author(s):  
Kyung Yong Lee ◽  
Sung Woong Bang ◽  
Sang Wook Yoon ◽  
Seung-Hoon Lee ◽  
Jong-Bok Yoon ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Origin Recognition Complex ◽  
S Phase ◽  
Cyclin Dependent Kinase ◽  
Replication Origins ◽  
Eukaryotic Chromosome ◽  
M Phase ◽  
Cycle Dependent ◽  
Prereplicative Complex ◽  
Origin Recognition

During the late M to the G1 phase of the cell cycle, the origin recognition complex (ORC) binds to the replication origin, leading to the assembly of the prereplicative complex for subsequent initiation of eukaryotic chromosome replication. We found that the cell cycle-dependent phosphorylation of human ORC2, one of the six subunits of ORC, dissociates ORC2, -3, -4, and -5 (ORC2–5) subunits from chromatin and replication origins. Phosphorylation at Thr-116 and Thr-226 of ORC2 occurs by cyclin-dependent kinase during the S phase and is maintained until the M phase. Phosphorylation of ORC2 at Thr-116 and Thr-226 dissociated the ORC2–5 from chromatin. Consistent with this, the phosphomimetic ORC2 protein exhibited defective binding to replication origins as well as to chromatin, whereas the phosphodefective protein persisted in binding throughout the cell cycle. These results suggest that the phosphorylation of ORC2 dissociates ORC from chromatin and replication origins and inhibits binding of ORC to newly replicated DNA.

scholarly journals Human Minichromosome Maintenance Proteins and Human Origin Recognition Complex 2 Protein on Chromatin

1998 ◽  
Vol 273 (38) ◽  
pp. 24543-24549 ◽  
Author(s):  
Marion Ritzi ◽  
Martina Baack ◽  
Christine Musahl ◽  
Piotr Romanowski ◽  
Ron A. Laskey ◽  
...  
Keyword(s):  
Origin Recognition Complex ◽  
Human Origin ◽  
Minichromosome Maintenance ◽  
Origin Recognition
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