INFORMATION:
Protein can release trapped histones in the cell
2021-04-14
(Press-News.org) In the cell nucleus histones play a crucial role packaging DNA into chromatin. Histones are however very sticky to both DNA and RNA, so to ensure they are transported to the cell nucleus after synthesis and bind to the right portion of DNA to organize the chromatin, they are guarded by complexes of histone chaperones.
Histone chaperones are proteins that bind to histones to help protect them from non-specific binding events until they reach their goal. This process fails sometimes and histones get stuck during their supply to chromatin without any purpose.
In a study published in Molecular Cell, researchers have shown that the protein DNAJC9 holds an important role in safeguarding histones and thereby chromatin.
Active fixer joins passive bystanders
"Until now researchers have assumed that histone chaperones only act to passively shield histones. We have found out that DNAJC9 actively engages the cellular protein folding machinery - which means it actively recruits enzymes and molecular chaperones to redeploy histones that have been trapped," says assistant professor Colin Hammond, who has lead the study. Hammond is part of the Protein Memory Program in the Novo Nordisk Foundation Center for Protein Research at University of Copenhagen.
Once released from their trapped condition histones can re-engage histone chaperones like MCM2 and be assembled into nucleosomes to organize chromatin. When the protein DNAJC9 is mutated to lose its ability to recruit the protein folding machinery, the histones stay trapped and are thereby lost for proper chromatin deposition.
"This means that traditional histone chaperones cannot fully protect histone proteins from spurious interactions. Rather, the cell is dependent on the combined action of molecular chaperones and histone chaperones to safeguard these fundamentally important proteins during their dynamic lives," Colin Hammond underlines.
Strong collaboration necessary
The study is based on a strong international collaboration. Co-first author Hongyu Bao in Hongda Huang's lab and other partners from Southern University of Science and Technology in China, and Dinshaw Patel from Memorial Sloan Kettering Cancer Center, provided the structural discoveries of DNAJC9. The functional analysis was spear-headed by Colin Hammond in close collaboration with colleagues from the Proteomics Program at CPR, Ivo Hendriks and Michael Lund Nielsen, to dissect the function of the protein through in depth proteomic assays.
Relevant insights for cancer research
DNAJC9 is an essential protein in many cancer cell types and the levels of the protein correlate with the rates at which cancer cells proliferate. Chromatin in cancer cells may be more reliant on DNAJC9 compared to regular cells, and if this is the case DNAJC9 could be a target for the development of future cancer treatments.
"Although it's still early days, we hope this fundamental advance in our understanding of DNAJC9 biology helps to pinpoint a function essential for cancer cell viability with therapeutic potential," Colin Hammond says.
ELSE PRESS RELEASES FROM THIS DATE:
Transforming circles into squares
2021-04-14
Reconfigurable materials can do amazing things. Flat sheets transform into a face. An extruded cube transforms into dozens of different shapes. But there's one thing a reconfigurable material has yet to be able to change: its underlying topology. A reconfigurable material with 100 cells will always have 100 cells, even if those cells are stretched or squashed.
Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a method to change a cellular material's fundamental topology at the microscale. The research is published in Nature.
"Creating ...
Get your head in the game -- One gene's role in cranial development
2021-04-14
Researchers from Tokyo Medical and Dental University (TMDU) use genetic engineering in mice to further understand how cell fate is determined in the head
Tokyo, Japan - Mammalian embryonic development is an extremely complex and precise process. Specific molecular events act as cues that tell cells in the embryo where to move and what type to mature into. The expression levels of different genes in these cells can change at certain points of development, helping produce the signals that further the progression. Now, researchers at Tokyo Medical and Dental University ...
Short duration of the Yixian Formation and 'Chinese Dinosaurs Pompeii'
2021-04-14
The Early Cretaceous Jehol Biota, renowned for its exceptionally well preserved volcanic-influenced ecosystem, was buried in lacustrine and occasionally fluvial sediments in northern Hebei and western Liaoning, China. It includes large amount of evolutionarily significant taxonomy, e.g. feathered dinosaurs, early birds, mammals and flowering plants, representing one of the most diversified terrestrial biotas of the Mesozoic and providing exceptional windows into some major fundamental issues in earth and biological sciences, such as the origins of birds and angiosperm, and co-evolution of life and environments.
The evolutionary radiation of the Jehol Biota can be broadly divided to ...
Suicides fallen by 4% during the Covid-19 pandemic
2021-04-14
In Austria, suicides have fallen by 4% since the start of the Covid-19 pandemic in March 2020, thereby consolidating the pre-2019 trend. An international study now shows that this pattern is similar to the global suicide trends during the initial phase of the coronavirus pandemic up until the end of October. "Figures are now also available from Statistik Austria for the whole of 2020 and these confirm the results of the study," says Thomas Niederkrotenthaler from the Center for Public Health (Department of Social and Preventive Medicine), who took part in the study on behalf of MedUni Vienna along with Paul Plener, Head of the Department of Child and Adolescent Psychiatry. A total of around 70 scientists in 21 countries were involved in the study. On average, the trends were found ...
Roadside invader: The higher the traffic, the easier the invasive common ragweed disperses
2021-04-14
Common ragweed is an annual plant native to parts of the United States and southern Canada. It's an invasive species that has spread to Europe. An important agricultural weed, this plant is particularly well-adapted to living at roadsides, and there are several theories why.
Its rapid expansion in Europe can't be explained by its natural dispersal rate, which is limited to distances of around 1 meter. Rather, there are other factors in play, human-mediated, that support its invasion success - along roads, for example, it spreads mainly thanks to agricultural machineries, soil movements, roadside maintenance and ...
Climate change is making it harder to get a good cup of coffee
2021-04-14
Ethiopia may produce less specialty coffee and more rather bland tasting varieties in the future. This is the result of a new study by an international team of researchers that looked at the peculiar effects climate change has on Africa's largest coffee producing nation. Their results are relevant both for the country's millions of smallholder farmers, who earn more on specialty coffee than on ordinary coffee, as well as for baristas and coffee aficionados around the world.
"Climate change has conflicting impacts on coffee production in Ethiopia. The area that is suitable for average quality coffee might actually increase ...
Novel diabetes subgroups show differences in biomarkers of inflammation
2021-04-14
Chronic inflammation is increasingly a focus of research. A recent study has now identified differences in indicators of inflammation between novel diabetes subgroups. But what does this mean for the future?
Symptoms that increase with age, such as cardiovascular disease, kidney damage or dementia, are common consequences of type 2 diabetes. In addition to metabolic disorders, chronic inflammatory reactions are important causes. The inflammatory cytokines typical for this can have numerous effects on various organs. One of the consequences of this is that the organs ...
Innovative technique developed to destroy cancerous kidney cells
2021-04-14
An innovative new technique that encourages cancer cells in the kidneys to self-destruct could revolutionise the treatment of the disease, a new study in the journal Pharmaceutics reports.
During this unique study, researchers from the University of Surrey and Sechenov First Moscow State Medical University in Russia investigated whether certain naturally occurring proteins within the body can be used to treat cancer.
Focusing on cathepsin S, a member of the lysosomal cathepsin proteins that are known to affect cancer progression, and p21 BAX, a protein that can stimulate cell destruction, researchers found that both can be deployed simultaneously ...
Twice as good: Combining mask wearing, social distancing suppresses COVID-19 virus spread
2021-04-14
BROOKLYN, New York, Wednesday, April 14, 2021 - Studies show wearing masks and social distancing can contain the spread of the COVID-19 virus, but their combined effectiveness was not precisely known.
Researchers at the New York University Tandon School of Engineering and Politecnico di Torino in Italy developed a network model to study the effects of these two measures on the spread of airborne diseases like COVID-19. The model shows viral outbreaks can be prevented if at least 60% of a population complies with both measures.
"Neither social distancing nor mask wearing alone are likely sufficient to halt the spread of COVID-19, unless almost the entire population adheres to the single measure," said Maurizio Porfiri, institute ...
Cultivating Matsutake, valuable edible fungi
2021-04-14
Costing anywhere from 15 to 70 dollars per mushroom depending on the quality, matsutake mushrooms are some of the most valuable edible fungi in the world. Revered for their delicate scent, matsutake mushrooms are cooked in rice or soups as an Autumn celebration delicacy in Japan. However, there is no way to cultivate matsutake mushrooms and naturally occurring habitats are decreasing with fewer forests conducive to their growth with the changing climate.
Corresponding author Professor Akiyoshi Yamada of Shinshu University's Department of Agriculture, Department of Bioscience and Biotechnology, and Institute for Mountain Science with 9 other researchers set out to present concrete evidence that matsutake spores germinate, reach the roots of the host, and coexist to produce offspring that ...