To ensure efficient genome duplication, cells have evolved numerous factors that promote unperturbed DNA replication, and protect, repair and restart damaged forks.
Here we identify DONSON as a novel fork protection factor, and report biallelic DONSON mutations in 29 individuals with microcephalic dwarfism. We demonstrate that DONSON is a replisome component that stabilises forks during genome replication. Loss of DONSON leads to severe replication-associated DNA damage arising from nucleolytic cleavage of stalled replication forks. Furthermore, ATR-dependent signalling in response to replication stress is impaired in DONSON-deficient cells, resulting in decreased checkpoint activity, and potentiating chromosomal instability. Hypomorphic mutations substantially reduce DONSON protein levels and impair fork stability in patient cells, consistent with defective DNA replication underlying the disease phenotype.
In summary, we identify mutations in DONSON as a common cause of microcephalic dwarfism, and establish DONSON as a critical replication fork protein required for mammalian DNA replication and genome stability.
The COVID-19 pandemic continues to spread rapidly and overwhelm health systems around the world. To cope with this unprecedented usage of healthcare resources, increasingly novel solutions are being brought into the fray. Telemedicine has been thrust into the spotlight in the fight against COVID-19 and is being employed in many different ways to better tackle the challenges. Telemedicine will likely have a more permanent place in traditional healthcare delivery long after COVID-19 is over as users and providers recognise its utility.
Childhood onset clinical syndromes involving intellectual disability and dysmorphic features, such as polydactyly, suggest common developmental pathways link seemingly unrelated phenotypes. We identified a consanguineous family of Saudi origin with varying complex features including intellectual disability, speech delay, facial dysmorphism and polydactyly. Combining, microarray based comparative genomic hybridisation (CGH) to identify regions of homozygosity, with exome sequencing, led to the identification of homozygous mutations in five candidate genes (RSPH6A, ANKK1, AMOTL1, ALKBH8, TRAPPC6A), all of which appear to be pathogenic as predicted by Proven, SIFT and PolyPhen2 and segregate perfectly with the disease phenotype. We therefore looked for differences in expression levels of each protein in HEK293 cells, expressing either the wild-type or mutant full-length cDNA construct. Unexpectedly, wild-type TRAPPC6A appeared to be unstable, but addition of the proteasome inhibitor MG132 stabilised its expression. Mutations have previously been reported in several members of the TRAPP complex of proteins, including TRAPPC2, TRAPPC9 and TRAPPC11, resulting in disorders involving skeletal abnormalities, intellectual disability, speech impairment and developmental delay. TRAPPC6A joins a growing list of proteins belonging to the TRAPP complex, implicated in clinical syndromes with neurodevelopmental abnormalities.
Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed cancers worldwide. Majority of patients with HCC are diagnosed in the advanced stages of disease and hence they are only suitable for palliative therapy. TACE (transarterial chemoembolization) is the most commonly used treatment for unresectable HCC. It is however unclear if TACE improves the quality of life (QoL) in patients with HCC. The aim of this review is to evaluate the impact of TACE on QoL of HCC patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.