Breaking News
January 16, 2019 - GoFundMe CEO: ‘Gigantic Gaps’ In Health System Showing Up In Crowdfunding
January 16, 2019 - Induced neuronal cells derived from fibroblasts are similar to neurons in the brain
January 16, 2019 - New study finds link between childhood abuse and suicide in later life
January 16, 2019 - Lifestyle and health factors that are good for the heart can also prevent diabetes
January 16, 2019 - Scientists take another step in understanding bacteria that cause Salmonella epidemic
January 16, 2019 - Look to Your Aunts, Uncles and Parents for Clues to Your Longevity
January 16, 2019 - Study finds ADHD drugs are unlikely to cause cardiac damage in children who take them
January 16, 2019 - Call The Midwife! (If The Doctor Doesn’t Object)
January 16, 2019 - Changes in hippocampal structural connectivity differentiate responders of electroconvulsive therapy
January 16, 2019 - Study sheds light on the deadly venom of Mojave rattlesnakes
January 16, 2019 - University of Nebraska to develop new drugs that prevent and counteract effects of radiation exposure
January 16, 2019 - Sugar-based stent makes precarious sewing process easier
January 16, 2019 - FDA-approved drug hampers cancer metastasis in animal model, shows study
January 16, 2019 - Childhood body composition may play a role in future respiratory health
January 16, 2019 - Outdated commissioning methods are failing mental health services in the UK, reveals report
January 16, 2019 - Unconventional immune cells trigger disturbed cytokine production in human spondyloarthritis
January 16, 2019 - Patients Turn To GoFundMe When Money And Hope Run Out
January 16, 2019 - Researchers develop novel viral identification method
January 16, 2019 - Study proposes improvements in pharmacological study of cognitive function enhancers in schizophrenia
January 16, 2019 - Study points to potential new biomarker and drug target for amyotrophic lateral sclerosis
January 16, 2019 - Differences in geographic origin of genes may affect mitochondrial function
January 16, 2019 - Study analyzes vaccine-preventable infections in children who receive solid organ transplants
January 16, 2019 - MiRagen Announces New Clinical Data in Patients With Three Different Types of Blood Cancers Treated With Cobomarsen
January 16, 2019 - Scientists uncover why knee joint injury leads to osteoarthritis
January 16, 2019 - Salk team uses new model to study health effects of AMP-activated protein kinase
January 16, 2019 - Research reveals novel approach to suppressing chemotherapy-induced tumor growth
January 16, 2019 - Researchers reveal how fasting leads to better overall health
January 16, 2019 - Deprivation and neglect in early childhood have impact on cognitive functioning in adolescence, shows study
January 16, 2019 - Training Students to use Imaging Techniques: NMR and EPR
January 16, 2019 - Nerve transfer surgery restores arm movement in children with acute flaccid myelitis
January 16, 2019 - Exelixis Announces U.S. FDA Approval of Cabometyx (cabozantinib) Tablets for Previously Treated Hepatocellular Carcinoma
January 16, 2019 - DNA vaccine reduces both toxic proteins linked to Alzheimer’s
January 16, 2019 - Even in the U.S., poor women often can't afford tampons, pads
January 16, 2019 - One time use of Marijuana could affect teen brains finds study
January 16, 2019 - Persistent Opioid Use High in Head, Neck Cancer Patients
January 16, 2019 - Questions to ask your doctor about post pregnancy care: MedlinePlus Medical Encyclopedia
January 16, 2019 - Neurons with good housekeeping are protected from Alzheimer’s
January 16, 2019 - Is mindfulness worthy of all the hype?
January 16, 2019 - Physical Activity, Any Type or Amount, Cuts Health Risk from Sitting
January 16, 2019 - New understanding in the evolution of human feet
January 15, 2019 - AHA: New Cholesterol Guidelines Put Ethnicity in the Spotlight
January 15, 2019 - Different brain areas linked to smoking and drinking
January 15, 2019 - Henry Marsh shares insights into neurosurgery and more at Dean’s Lecture Series
January 15, 2019 - Want to Live Longer? For Just 30 Minutes a Day, Do Anything Else But Sit
January 15, 2019 - The Current issue of “The view from here” is concerned with Targets
January 15, 2019 - Plain packaging sparked tobacco price rises, new study finds
January 15, 2019 - Sedentary lifestyles can be unhealthy, physical activity can lower risk
January 15, 2019 - Gut microbiome may help prevent development of cow’s milk allergy
January 15, 2019 - Lesbian, gay and bisexual individuals more likely to suffer severe substance use disorders
January 15, 2019 - New England Journal of Medicine Publishes Positive Results of the Pivotal Trial of Cablivi (caplacizumab) for Rare Blood Clotting Disorder
January 15, 2019 - Levels of inflammatory marker (CRP) linked to housing type and tenure
January 15, 2019 - Three gifts I’m glad I gave myself in 2018
January 15, 2019 - Columbia’s Pediatrics Department Names New Vice Chairs, Expands Leadership
January 15, 2019 - US FDA Accepts Regulatory Submissions for Review of Tafamidis to Treat Transthyretin Amyloid Cardiomyopathy
January 15, 2019 - Staying fit can cut your risk of heart attack by half
January 15, 2019 - Vitamin D supplements are of no gain to those over 70, study shows
January 15, 2019 - Scientists create comprehensive new method to predict breast cancer risk
January 15, 2019 - Research shows connection between social media use and impaired risky decision-making
January 15, 2019 - FDA Approves Expanded Use of Adacel (Tdap) Vaccine for Repeat Vaccination
January 15, 2019 - Treating spinal pain with replacement discs made of ‘engineered living tissue’ moves closer to reality
January 15, 2019 - Providers Walk ‘Fine Line’ Between Informing And Scaring Immigrant Patients
January 15, 2019 - Outcomes Poorer for Medicaid Beneficiaries With STEMI
January 15, 2019 - Decorative Products on Foods Can Be Unsafe
January 15, 2019 - A dream of sustainable surgery in Uganda
January 15, 2019 - Study shows how herpes viruses and tumors have learned to manipulate the same ancient RNA
January 15, 2019 - Common Heart, Diabetes Meds May Help Ease Mental Illness
January 15, 2019 - Stress and trauma in earliest years linked to reduced hippocampal volume in adolescence
January 15, 2019 - Scientists identify endogenous activator of sigma-1 receptors in human cells
January 15, 2019 - MAR treatments unlikely to be cause of premature or low birth weight babies
January 15, 2019 - Parental CPTSD increases transmission of trauma to offspring of Tutsi genocide survivors
January 15, 2019 - High-fat diets shown to increase blood pressure
January 15, 2019 - New institute for food safety to be established in Netherlands
January 15, 2019 - Keele University researchers receive £2.4 million grant to help reduce overprescribing of opioids
January 15, 2019 - Synthetic compound reverses mutant p53 aggregate accumulation, study shows
January 15, 2019 - First elder care robot tested in a WSU smart home apartment
January 15, 2019 - Oxford researchers explore relationship between technology use and adolescent mental health
January 15, 2019 - From microbiome research to healthier and sustainable foods
January 15, 2019 - How coaching moms and dads improves infants’ language skills
January 15, 2019 - Precision health approach tapped to identify causes of poverty
January 14, 2019 - DNA origami can accurately measure how antibodies interact with several antigens
Free magnesium ions regulate chromosome shape, new tool shows

Free magnesium ions regulate chromosome shape, new tool shows

image_pdfDownload PDFimage_print

A new chemical tool, MARIO, shows how free Mg2+ ions regulate chromosome shape

Japanese researchers report a new ion detector, MARIO. Using it, they show that changes in the intracellular concentration of free magnesium ions (Mg2+) is critical for the chromosome folding that must occur for cells to divide. The findings, which can be read in Current Biology, provide a new mechanism for chromosome organization.

Cell division is essential for new cells to form in the body, be it during normal growth or to repair lost or damaged cells. During cell division, chromosomes begin to condense and remain so until the division is complete. A number of proteins in the cell control the condensation, but so too do free ions such as Mg2+.

“Chromosomes are negatively charged. Free cations like Mg2+ neutralize the charge so that the chromosomes can condense during cell division,” explains Prof. Kazuhiro Maeshima at the National Institute of Genetics (NIG), who studies the 3D dynamics of DNA and led the study.

Although it is known that Mg2+ might have an important role in chromosome rearrangement, quantitatively measuring Mg2+ concentration during cell division has been a challenge. Prof. Maeshima therefore teamed with Osaka University Prof. Takeharu Nagai, a leader in the development of chemical probes for intracellular signaling. Together, they formulated MARIO (Magnesium Ratiometric Indicator for Optical Imaging), a fluorescent probe that measures Mg2+ concentration.

MARIO is based on a calcium indicator known as YC3.60 and is composed of enhanced cyan fluorescent protein, the yellow fluorescent protein VENUS, and a Mg2+-binding domain found in bacteria known as CorA. Mg2+ binding to CorA causes a structural change in MARIO that changes the fluorescence signal.

“We could improve MARIO’s performance, both in terms of Mg2+affinity and dynamic range, by truncating CorA and by introducing random mutations into the structure,” says Nagai.

Mg2+ itself is abundant in the cell, but not in free form. Instead it is usually captured by ATP. Using MARIO, the researchers found that during cell division, free Mg2+ greatly increases, enabling the chromosomes to condense. The increase peaked during the transition from metaphase to anaphase, which marks the period in cell division that the cell membrane begins showing signs of breaking into two cells.

“We found a clear relationship between ATP levels and free Mg2+,” says Maeshima. “The less ATP, the more Mg2+ and the more chromosome condensation. If we decrease ATP levels, then chromosomes even more condense. We propose a novel mechanism by which dynamics are regulated during cell division, in which ATP-bound Mg2+is released by the hydrolysis of ATP.”

Because cell division is an energy intensive event, it is presumed that the cell will consume more ATP.

“We are not sure what causes the ATP demand. But a number of actions are taken during cell division, so we are not surprised to see Mg2+ levels increase.

A number of diseases like cancer are caused by abnormalities in cell division. We expect that understanding how chromosome condensation is regulated will help us understand how these diseases develop and possible ways to treat them,” says Maeshima.

Source:

http://resou.osaka-u.ac.jp/en/research/2018/20180119_2

Tagged with:

About author

Related Articles