Cdt1 overexpression drives colorectal carcinogenesis through origin overlicensing and DNA damage
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE212710 | GEO | 2023/09/01
REPOSITORIES: GEO
Similar Datasets
Project description:rs04-06_cdt1 - cdt1 - CDT1 is a protein of the pre-replication complex, and accumulates during the G1-S transition, thus play a major role in S-phase entry - Comparison of 3 independant RNAi lines Keywords: normal vs rnai mutant comparaison
2007-06-20 | GSE7997 | GEO
Project description:rs04-06_cdt1 - cdt1 - CDT1 is a protein of the pre-replication complex, and accumulates during the G1-S transition, thus play a major role in S-phase entry - Comparison of 3 independant RNAi lines Keywords: normal vs rnai mutant comparaison
2007-08-09 | GSE8698 | GEO
Project description:au13-04_cdtbis; cdt1_bis crl mutants and CDT1-RNAi lines have very similar macroscopic phenotypes as well as identical defects in plastid division and biogenesis. Our goal wwas to determine how much of these similarities originated from similar alterations of gene expression. Plantlets of crl mutant and CDT1-RNAi lines were grown in vitro on MS1/2 medium for 14 days. CDT1-RNAi lines were compared to the corresponding wild-type (Ws), whereas crl mutants were compared to their wild-type siblings and are in the Col0 ecotype.
2013-09-01 | GSE48465 | GEO
Project description:au13-04_cdtbis; cdt1_bis crl mutants and CDT1-RNAi lines have very similar macroscopic phenotypes as well as identical defects in plastid division and biogenesis. Our goal wwas to determine how much of these similarities originated from similar alterations of gene expression. Plantlets of crl mutant and CDT1-RNAi lines were grown in vitro on MS1/2 medium for 14 days. CDT1-RNAi lines were compared to the corresponding wild-type (Ws), whereas crl mutants were compared to their wild-type siblings and are in the Col0 ecotype. 4 dye-swap - normal vs rnai mutant comparaison, normal vs transgenic comparaison
2013-09-01 | E-GEOD-48465 | biostudies-arrayexpress
Project description:During S-phase of the eukaryotic cell cycle, controls exist to ensure that replication origins fire only once and become inactivated after traverse of a replication fork. Failure of these controls results in local amplification of the genome which can lead to gene copy increases important for both evolutionary change and for somatic genetic diseases such as cancer. It is not known what characteristics of replication origins might predispose them to escape from these controls. We have investigated this problem in the fission yeast Schizosaccharomyces pombe by characterizing regions of the genome which become amplified when the DNA synthesis initiation factors cdc18 (cdc6) and cdt1 are co-overexpressed and by defining origins of replication responsible for local amplification. We find that a single origin can be necessary but not sufficient to induce ectopic local amplification and that origins likely to escape the regulation of one firing per cell cycle are among the most AT-rich, efficient and early firing in the genome, and are embedded in long intergenes. Replication origins with these features may be more prone to re-fire within a round of replication potentiating genome instability.
2010-08-13 | E-MTAB-139 | biostudies-arrayexpress
Project description:The origin recognition complex (ORC) nucleates DNA replication initiation in eukaryotic cells. This six-protein complex binds replication origin DNA, recruits other initiation factors and facilitates loading of the DNA helicase. Studying the function of individual ORC subunits during pre-RC formation has been hampered by the requirement of most subunits for DNA binding. In this study, we investigate the function of the S. cerevisiae Orc6 subunit, the only subunit not required for DNA binding. In vivo, depletion of Orc6 inhibits pre-replicative complex (pre-RC) assembly and maintenance. In vitro, ORC lacking Orc6 fails to interact with Cdt1 and to load the Mcm2-7 helicase onto origin DNA. We demonstrate that two regions of Orc6 bind Cdt1 directly and that the extreme C-terminus of Orc6 (Orc6-CTD) interacts tightly with the remaining five ORC subunits. Replacing Orc6 with a fusion protein linking Cdt1 to the Orc6-CTD results in an ORC complex that loads Mcm2-7 onto DNA. Interestingly, this complex can only perform a single round of Mcm2-7 loading, suggesting that a dynamic association of Cdt1 with ORC is required for multiple rounds of pre-RC assembly. Keywords: ChIP-chip
2007-11-14 | GSE9318 | GEO
Project description:DNA replication is initiated at multiple sites or origins enriched with AT-rich sequences at various times during the S-phase. While current studies of genome-wide DNA replication profiles have focused on the timing of replication and the location of origins, the efficiency of replication/firing at various origins remains unclear. In this study, we show different efficiencies of DNA replication at various loci by using ORF-specific DNA microarrays. DNA copy-number increases as a function of time at individual loci are approximated to near-sigmoidal models for estimation of replication initiation and completion timings in HU-challenged cells. Duplicating times (from initiation to completion) vary from loci to loci, partly contributing to various firing efficiencies at origins. DNA replication timing profiles are strikingly similar to the reported patterns of enriched ssDNA, suggesting that majority stalled forks are restored for resumption of DNA replication. Although the DNA replication timing profiles are disrupted in HU-challenged cds1? cells, ~85% of potential origins overlapped with those found in wild type cells, significantly, most of which represents inefficiently fired origins in wild type cells. Together, our result indicates that replication checkpoint plays a role in monitoring efficient origins and thus maintaining global DNA replication patterns in HU-challenged cells. Keywords: WT or Cds1 HU synchronized cells released in HU free media and harvested at different time points vs WT or Cds1 synchronized with HU for 3 hrs. We analyzed 32 arrays for WT and 38 arrays for Cds1 cells which were synchronized with HU and released in HU free media and harvested at different time points. At least two biological repeats were done for each time points.
2007-08-14 | E-GEOD-6977 | biostudies-arrayexpress
Project description:One of the long-standing questions in eukaryotic DNA replication is the mechanisms that determine where and when a particular segment of the genome is replicated. Cdc7/Hsk1 is a conserved kinase required for initiation of DNA replication, and may affect the site selection and timing of origin firing. We identified rif1∆, a null mutant of rif1+, a conserved telomere binding factor, as an efficient bypass mutant of fission yeast hsk1. Extensive deregulation of dormant origins over a wide range of the chromosomes occurs in rif1∆ in the presence or absence of HU. At the same time, many early-firing, efficient origins are suppressed or delayed in firing timing in rif1∆. Rif1 binds not only to telomeres but also to many specific locations on the arm segments that only partially overlap with the pre-Replicative Complex assembly sites, although Rif1 tends to bind in the vicinity of the late/ dormant origins activated in rif1∆. The binding to the arm segments occurs through M to G1 phase in a manner independent of Taz1 and appears to be essential for the replication timing program during normal cell cycle. Our data demonstrate that Rif1 is a critical determinant of origin activation program on the fission yeast chromosomes. BrdU incorporation profiles at early S-phase in Wild vs rif1∆. Cdc45 binding profiles at early S-phase in Wild vs rif1∆. Rif1 binidng sites aroud G1/S boudary and at M-phase. Mcm4 binding sites in wild, hsk1-89 temperature mutant and rif1∆.
2011-12-13 | GSE34369 | GEO
Project description:DNA replication is initiated at multiple sites or origins enriched with AT-rich sequences at various times during the S-phase. While current studies of genome-wide DNA replication profiles have focused on the timing of replication and the location of origins, the efficiency of replication/firing at various origins remains unclear. In this study, we show different efficiencies of DNA replication at various loci by using ORF-specific DNA microarrays. DNA copy-number increases as a function of time at individual loci are approximated to near-sigmoidal models for estimation of replication initiation and completion timings in HU-challenged cells. Duplicating times (from initiation to completion) vary from loci to loci, partly contributing to various firing efficiencies at origins. DNA replication timing profiles are strikingly similar to the reported patterns of enriched ssDNA, suggesting that majority stalled forks are restored for resumption of DNA replication. Although the DNA replication timing profiles are disrupted in HU-challenged cds1? cells, ~85% of potential origins overlapped with those found in wild type cells, significantly, most of which represents inefficiently fired origins in wild type cells. Together, our result indicates that replication checkpoint plays a role in monitoring efficient origins and thus maintaining global DNA replication patterns in HU-challenged cells. Keywords: WT or Cds1 HU synchronized cells released in HU free media and harvested at different time points vs WT or Cds1 synchronized with HU for 3 hrs.
2007-08-14 | GSE6977 | GEO
Project description: Not available
| S-EPMC2533066 | biostudies-literature