Sister chromatid cohesion, mediated by the cohesin complex, is essential for faithful mitosis. Nevertheless, evidence suggests that the surveillance mechanism that governs mitotic fidelity, the spindle assembly checkpoint (SAC), is not robust enough to halt cell division when cohesion loss occurs prematurely. The mechanism behind this poor response is not properly understood. Using developing Drosophila brains, we show that full sister chromatid separation elicits a weak checkpoint response resulting in abnormal mitotic exit after a short delay. Quantitative live-cell imaging approaches combined with mathematical modeling indicate that weak SAC activation upon cohesion loss is caused by weak signal generation. This is further attenuated by several feedback loops in the mitotic signaling network. We propose that multiple feedback loops involving cyclin-dependent kinase 1 (Cdk1) gradually impair error-correction efficiency and accelerate mitotic exit upon premature loss of cohesion. Our findings explain how cohesion defects may escape SAC surveillance.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.celrep.2015.09.020 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The BLM-TOP3A-RMI1-RMI2 proximity map reveals that RAD54L2 suppresses sister chromatid exchanges.
EMBO Rep
January 2025
Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada.
Homologous recombination is a largely error-free DNA repair mechanism conserved across all domains of life and is essential for the maintenance of genome integrity. Not only are the mutations in homologous recombination repair genes probable cancer drivers, some also cause genetic disorders. In particular, mutations in the Bloom (BLM) helicase cause Bloom Syndrome, a rare autosomal recessive disorder characterized by increased sister chromatid exchanges and predisposition to a variety of cancers.
View Article and Find Full Text PDFDNA double strand breaks (DSBs) are widely considered the most cytotoxic DNA lesions occurring in cells because they physically disrupt the connectivity of the DNA double helix. Homologous recombination (HR) is a high-fidelity DSB repair pathway that copies the sequence spanning the DNA break from a homologous template, most commonly the sister chromatid. How both DNA ends, and the sister chromatid are held in close proximity during HR is unknown.
View Article and Find Full Text PDFHP1 Promotes the Centromeric Localization of ATRX and Protects Cohesion by Interfering Wapl Activity in Mitosis.
Front Biosci (Landmark Ed)
January 2025
The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University Health Science Center, 410013 Changsha, Hunan, China.
Background: α thalassemia/mental retardation syndrome X-linked (ATRX) serves as a part of the sucrose nonfermenting 2 (SNF2) chromatin-remodeling complex. In interphase, ATRX localizes to pericentromeric heterochromatin, contributing to DNA double-strand break repair, DNA replication, and telomere maintenance. During mitosis, most ATRX proteins are removed from chromosomal arms, leaving a pool near the centromere region in mammalian cells, which is critical for accurate chromosome congression and sister chromatid cohesion protection.
View Article and Find Full Text PDFCell Type Specific Suppression of Hyper-Recombination by Human RAD18 Is Linked to Proliferating Cell Nuclear Antigen K164 Ubiquitination.
Biomolecules
January 2025
Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
RAD18 is a conserved eukaryotic E3 ubiquitin ligase that promotes genome stability through multiple pathways. One of these is gap-filling DNA synthesis at active replication forks and in post-replicative DNA. RAD18 also regulates homologous recombination (HR) repair of DNA breaks; however, the current literature describing the contribution of RAD18 to HR in mammalian systems has not reached a consensus.
View Article and Find Full Text PDFHPV E6/E7-Induced Acetylation of a Peptide Encoded by a Long Non-Coding RNA Inhibits Ferroptosis to Promote the Malignancy of Cervical Cancer.
Adv Sci (Weinh)
January 2025
Department of Gynecology, Women's Hospital of Nanjing Medical University, Nanjing Women and Children's Healthcare Hospital, Nanjing Medical University, Nanjing, 210004, P. R. China.
Although a fraction of functional peptides concealed within long non-coding RNAs (lncRNAs) is identified, it remains unclear whether lncRNA-encoded peptides are involved in the malignancy of cervical cancer (CC). Here, a 92-amino acid peptide is discovered, which is named TUBORF, encoded by lncRNA TUBA3FP and highly expressed in CC tissues. TUBORF inhibits ferroptosis to promote the malignant proliferation of CC cells.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!