Breaking News
December 19, 2018 - Gut microbiome plays role in immune system regulation, study finds
December 19, 2018 - How MAPK translocation leads to drug resistance in melanoma
December 19, 2018 - Increasing prevalence of antibiotic resistance in the U.S. linked with occasional use
December 19, 2018 - Mind-body exercises may improve cognition in older adults
December 19, 2018 - Hepatitis C drug can eliminate chikungunya, yellow fever virus
December 19, 2018 - Separating male and female mice changes the way they smell, shows study
December 19, 2018 - FDA Approves Genentech’s Tecentriq in Combination With Avastin and Chemotherapy for the Initial Treatment of Metastatic Non-Squamous Non-Small Cell Lung Cancer
December 19, 2018 - Mediterranean Diet for Osteoarthritis | About OA
December 19, 2018 - Successful bladder repair using silk fibroid scaffolds
December 19, 2018 - Quidel receives CE mark to use Sofia 2 Lyme+ Fluorescent Immunoassay with Sofia 2 analyzer
December 19, 2018 - Horizon Discovery partners with C4XD to validate novel synthetic lethal oncology targets
December 19, 2018 - Research suggests a promising therapeutic target to treat or prevent metabolic disorders
December 19, 2018 - Split liver transplants could save children on wait list finds study
December 19, 2018 - Michigan-based food manufacturer ordered to discontinue operations after recurrent food safety violations
December 19, 2018 - Real-time neurofeedback controls Parkinson’s brainwaves
December 19, 2018 - Incorrect prescribing warnings in electronic prescribing systems
December 19, 2018 - New $1.6 million NIH grant supports study on a gene vital to circadian rhythms
December 19, 2018 - Racial Disparities Seen Among Teens Undergoing Flu Vaccination
December 19, 2018 - To resolve inflammation, location matters
December 19, 2018 - Dancing could help older women to perform their daily tasks
December 19, 2018 - Research identifies new therapeutic target for cancer treatment and tissue regeneration
December 19, 2018 - Energy costs, social isolation contribute to health risk of older adults in extreme weather
December 19, 2018 - Potential combination therapy against rare disease of the bone marrow could improve treatment
December 19, 2018 - Researchers aim to improve cognition, reverse weight gain in schizophrenia
December 19, 2018 - UC San Diego Health offers new DRG stimulation device for phantom limb pain
December 19, 2018 - Study examines relationship between growth restriction and risk of childhood mortality
December 19, 2018 - New study provides insights on increased risk of suicide in young patients visiting ED
December 19, 2018 - AHA: Thyroid Problems Linked to Worsening Heart Failure
December 19, 2018 - World-first coeliac disease vaccine enters Phase 2 trials
December 19, 2018 - RNA sequencing offers novel insights into the microbiome
December 19, 2018 - A promising, effective vaccine for common respiratory disease
December 19, 2018 - Protein may slow progression of emphysema, study finds
December 19, 2018 - Studying atrial fibrillation — and exploring new frontiers in precision health
December 19, 2018 - A New Way To Get College Students Through A Psychiatric Crisis — And Back To School
December 19, 2018 - Optum, UnitedHealthcare take action to help people affected by North Carolina winter storms
December 18, 2018 - Weight change in middle-aged, elderly Chinese Singaporeans related to increased risk of death
December 18, 2018 - Immune cells sacrifice themselves to protect us from invading bacteria
December 18, 2018 - Watching brain cells fire, with a twist of gravitational waves
December 18, 2018 - 2018 in Review
December 18, 2018 - Getting the Most Out of the CLARITY Technique
December 18, 2018 - NVF shoes provide a viable option for track and road racing
December 18, 2018 - CRISPR may restore effectiveness of chemotherapies used to treat lung cancer
December 18, 2018 - New app accurately measures and charts progression of skin wounds
December 18, 2018 - Persistent Discrimination ID’d Among Physician Mothers
December 18, 2018 - Cellphone technology developed to detect HIV
December 18, 2018 - A Stanford doctor hits the field with the 49ers — as their airway management physician
December 18, 2018 - The Rise of Anxiety Baking
December 18, 2018 - Just one night of sleep deprivation increases the urge to eat
December 18, 2018 - Study reveals mechanism behind failed remyelination in MS
December 18, 2018 - New genetic testing method increases the precision of biomarker analysis
December 18, 2018 - Simple technique to effectively treat underdiagnosed cause of debilitating chest pain
December 18, 2018 - Barbershop-based medical intervention can successfully lower blood pressure, new data shows
December 18, 2018 - Food labels have caused changes in consumers’ intake and industry’s use of key additives
December 18, 2018 - Sickest children could benefit from split liver transplants
December 18, 2018 - Scientists create patient-specific model to identify most effective treatment for appendix cancer
December 18, 2018 - ‘Little Foot’ endocast reveals a small brain combining ape-like and human-like features
December 18, 2018 - New therapy for childhood blindness shows ‘very promising’ results
December 18, 2018 - Researchers discover promising new compound against Buruli ulcer
December 18, 2018 - Study finds significant use of traditional, complementary and alternative medicines in Sub-Saharan Africa
December 18, 2018 - California Farm Implicated in Outbreak of E. coli Tied to Romaine Lettuce
December 18, 2018 - Mobile health has power to transform HIV/AIDS nursing
December 18, 2018 - Celiac Vaccine in Clinical Trials at Columbia
December 18, 2018 - Research into mental health first aid prompts practical guidance and resources for workplace
December 18, 2018 - Researcher conducts study to investigate peripheral blood markers of Alzheimer’s disease
December 18, 2018 - Researchers identify link between mucus in the small airways and pulmonary fibrosis
December 18, 2018 - EU Commission’s Health Policy Platform to host EKHA program on transplantation
December 18, 2018 - Survivors of childhood Hodgkin lymphoma have high risk of developing solid tumors
December 18, 2018 - Small changes to cafeteria design can get kids to eat healthier, new assessment tool finds
December 18, 2018 - From Machines to Cyclic Compounds
December 18, 2018 - New study reveals best assessment tools to establish delirium severity
December 18, 2018 - Rice University scientists develop synthetic protein switches to control electron flow
December 18, 2018 - Home-based pulmonary function monitoring for teens with Duchenne muscular dystrophy
December 18, 2018 - Researchers identify potential target for new breast cancer treatments
December 18, 2018 - National Biofilms Innovation Centre award grant to Neem Biotech for novel anti-biofilm drug development
December 18, 2018 - Artificial intelligence and the future of medicine
December 18, 2018 - Montana State doctoral student receives grant for her work to improve neuroscience tool
December 18, 2018 - Early postpartum initiation of opioids associated with persistent use
December 18, 2018 - Russian scientists identify molecular ‘switch’ that could be target for treatment of allergic asthma
December 18, 2018 - Surgeons make more mistakes in the operating room during stressful moments, shows study
December 18, 2018 - Immune cells explode themselves to inform about the danger of invading bacteria
Study links cell size with commitment to division

Study links cell size with commitment to division

image_pdfDownload PDFimage_print

How does a cell know when to divide? We know that hundreds of genes contribute to a wave of activity linked to cell division, but to generate that wave new research shows that cells must first grow large enough to produce four key proteins in adequate amounts. The study, published today in Cell Systems, offers a path for controlling the balance between cell growth and division, which is implicated in countless diseases, including cancers.

“For years we have known that cells must reach a size threshold prior to cell division, but how cells know when they reach that threshold has been a mystery,” said Catherine Royer, lead author, along with Mike Tyers of the University of Montreal. Royer is Biocomputation and Bioinformatics Constellation Professor and Professor in the Department of Biological Sciences at Rensselaer Polytechnic Institute, and member of the Rensselaer Center for Biotechnology and Interdisciplinary Studies (CBIS). “Something sets the threshold and something senses it. This research establishes the mechanism behind this core machinery in budding yeast cells.”

The research also resolves the question of why cells with access to a nutrient-poor environment divide at a smaller size. Both findings are related to the abundance of the four key proteins required.

“Many diseases include an element of abnormal cell size and growth, and at the moment we have few means of controlling those aspects of cell growth,” said Deepak Vashishth, CBIS director. “This research marks a clear path toward targeting transcription factors to change that outcome. It’s a clear example of how translational medicine gets its start at Rensselaer.”

Royer and her team, which included researches from Rensselaer and the Université de Montréal, examined yeast cells, which divide by budding. As with most cells, yeast cells must first synthesize the necessary resources and grow in size, a phase of cell cycle known as G1. About 200 genes must be activated at the end of G1, and the research team examined five proteins–the transcription factors SBF and MBF, the transcriptional repressor Whi5, and the G1 cyclins Cin1 and Cin2–that are collectively required to initiate transcription of those 200 genes.

The researchers used a particle-counting technique to measure the absolute concentration of each of the five proteins present in cells as they grew in size. The technique relies on creating a very small optical volume and scanning “Number and Brightness” microscopy to gather data on light emitted from fluorescent-tagged proteins in a select volume of the cell. Calculations based on the relationship between average light intensity and fluctuations in light intensity reveal the number of molecules in that volume.

Royer found that as the cells grew in size, molecules of four of the five proteins examined reached a number great enough to bind to the estimated 400 binding sites on the 200 genes the proteins control. Commitment to division was triggered when the cell grew large enough to saturate the binding sites.

“In a small cell, there just weren’t enough of them to bind to all of the sites. As the cell grows, the concentration remains the same, but having the same concentration in a larger cell means that there are more molecules, and eventually enough to bind to the available sites,” said Royer. “It turns out that this system is a simple titration mechanism. It’s very straightforward biochemistry.”

The team grew cells in growth medium–a liquid designed to support yeast cell growth–with different kinds of nutrients. When the team examined cells grown in medium with poor nutrients, they discovered that those cells were “up-regulating,” producing more molecules of the four key proteins given their cell size, and therefore triggering commitment to division at a smaller size. The finding explains why cells grown in a nutrient-poor environment are smaller in size.

“It’s counter-intuitive, but at a certain level, it makes sense,” Royer said. “If you’re a yeast cell, and you are in a nutrient-poor environment, your best bet is survival of the colony rather than the individual. And so you divide at a smaller size to support the colony.”

“G1/S Transcription Factor Copy Number is a Growth-Dependent Determinant of Cell Cycle Commitment in Yeast” appears in Cell Systems. Continued research will be funded through the National Science Foundation.

Research on cell size homeostasis fulfills The New Polytechnic, an emerging paradigm for higher education which recognizes that global challenges and opportunities are so great they cannot be adequately addressed by even the most talented person working alone. Rensselaer serves as a crossroads for collaboration — working with partners across disciplines, sectors, and geographic regions — to address complex global challenges, using the most advanced tools and technologies, many of which are developed at Rensselaer. Research at Rensselaer addresses some of the world’s most pressing technological challenges — from energy security and sustainable development to biotechnology and human health. The New Polytechnic is transformative in the global impact of research, in its innovative pedagogy, and in the lives of students at Rensselaer.

Source:

https://news.rpi.edu/content/2018/05/23/how-cell-knows-when-divide

Tagged with:

About author

Related Articles