Biology News Net
RSS 2.0 Feed
Molecular & Cell Biology

Category: Molecular & Cell Biology


Stylized graphic of SEC-SAXS data (with cyan cross-section showing the elution profile and magenta cross-section showing scattering profile) and the structure of the activated phenylalanine hydroxylase
Using a powerful combination of techniques from biophysics to mathematics, researchers have revealed new insights into the mechanism of a liver enzyme that is critical for human health. The enzyme, phenylalanine hydroxylase, turns the essential amino acid phenylalanine -- found in eggs, beef and many other foods and as an additive in diet soda -- into tyrosine, a precursor for multiple important neurotransmitters.

A new study from MIT neuroscientists reveals that a gene mutation associated with autism plays a critical role in the formation and maturation of synapses -- the connections that allow neurons to communicate with each other.

Unlike aspirin, bone marrow doesn't come with a neatly printed label with dosage instructions. However, a new study published in Cell Reports provides clues about how the dose of transplanted bone marrow might affect patients undergoing this risky procedure, frequently used to treat cancer and blood diseases.


These are DNA double-strand breaks, introduced by ionizing radiation or other mechanisms, are repaired rapidly and precisely in normal cells (right pathway). In contrast, compromised Tel1 activation with inefficient end...
A group of researchers at Osaka University found that if DNA damage response (DDR) does not work when DNA is damaged by radiation, proteins which should be removed remain instead, and a loss of genetic information can be incited, which, when repaired incorrectly, will lead to the tumor formation.

Voltage-gated calcium channels open in unison, rather than independently, to allow calcium ions into and activate excitable cells such as neurons and muscle cells, researchers with UC Davis Health System and the University of Washington have found.

Retroviral DNAs integrate into host genomes, but their expression is normally repressed by cellular defense mechanisms. As an Ludwig-Maximilians-Universitaet (LMU) in Munich team now shows, when these measures fail, accumulation of viral proteins may trigger programmed cell death.


Verrucosispora maris, the bacteria in which the enzyme was found.
Scientists at the Universities of Bristol and Newcastle have uncovered the secret of the 'Mona Lisa of chemical reactions' - in a bacterium that lives at the bottom of the Pacific Ocean.

A new study finds that the more than 90,000 species of mushrooms, molds, yeasts and other fungi found everywhere in the soil, water and air may owe their abilities to grow, spread, and even cause disease to an opportunistic virus they caught more than a billion years ago.


This is a tomographical slice of a budding yeast cell defective in condensin function (ycg1-2). The division septum advances on incompletely segregated chromosomes.
The cells in our bodies are constantly dividing. From embryonic development to adult life, cell division is necessary for tissue growth and renewal. During division, cells must duplicate their genetic material (or DNA) and ensure identical copies are passed along to the daughter cells. The entire process must work perfectly. If not, the next generation of cells will not have the genetic material necessary to function properly. Their role becomes especially relevant in situations in which cells proliferate rapidly, like embryonic development or tumor proliferation.


This is a snapping turtle.
The sex of many reptile species is set by temperature. New research reported in the journal GENETICS identifies the first gene associated with temperature-dependent sex determination in any reptile. Variation at this gene in snapping turtles contributes to geographic differences in the way sex ratio is influenced by temperature. Understanding the genetics of sex determination could help predict how reptiles will evolve in response to climate change.


A 3-D rendering of a fluorescence image maps the piconewton forces applied by T cells. The height and color indicates the magnitude of the applied force.
T cells, the security guards of the immune system, use a kind of mechanical "handshake" to test whether a cell they encounter is a friend or foe, a new study finds.

RNA polymerase II (Pol II), a key enzyme in our gene expression, is responsible for transcribing DNA into messenger RNA. Errors in transcription can cause deleterious effect upon repeated translation of erroneous mRNA into protein. Transcription infidelity may result in aging and human diseases such as cancer. During transcription, Pol II can detect the mis-incorporated RNA and backtrack to correct errors to ensure that each messenger RNA created will match with template DNA. However, it remains largely a mystery how Pol II controls the fidelity of gene transcription.

A microscope about the size of a penny is giving scientists a new window into the everyday activity of cells within the spinal cord. The innovative technology revealed that astrocytes--cells in the nervous system that do not conduct electrical signals and were traditionally viewed as merely supportive--unexpectedly react to intense sensation.

Scientists from Princeton University and Uppsala University in Sweden have identified a specific gene that within a year helped spur a permanent physical change in a finch species in response to a drought-induced food shortage. The findings provide a genetic basis for natural selection that, when combined with observational data, could serve as a comprehensive model of evolution.

A new study from the group of Holger Gerhardt (VIB/KU Leuven/Cancer Research UK/ MDC/BIH Berlin) in collaboration with Katie Bentley's Lab (Cancer Research UK/BIDMC-Harvard Medical School) addresses a long standing question in the wider field of developmental biology and tissue patterning in general, and in the vascular biology field in particular: 'What are the fundamental mechanisms controlling size and shape of tubular organ systems'. Whereas the most obvious way to grow a tube in size would be to add more building blocks (by proliferating cells) to enlarge its circumference, or to increase the size of the building blocks (the cells, hypertrophy), an alternative way would be to rearrange existing building blocks. Benedetta Ubezio, Raquel Blanco and colleagues under the direction of Holger Gerhardt and Katie Bentley now show that cell rearrangement is the way blood vessels switch from making new branches to increasing the size of a branch. The researchers also found that this switch is triggered by synchronization of cells under the influence of increasing levels of the growth factor VEGFA.


This is a skeletal preparation of a late stage skate embryo.
Latest analysis shows that human limbs share a genetic programme with the gills of cartilaginous fishes such as sharks and skates, providing evidence to support a century-old theory on the origin of limbs that had been widely discounted.

If genes form the body's blueprint, then the layer of epigenetics decides which parts of the plan get built. Unfortunately, many cancers hijack epigenetics to modulate the expression of genes, thus promoting cancer growth and survival. A team of researchers led by Tatiana Kutateladze, PhD, University of Colorado Cancer Center investigator and professor in the Department of Pharmacology at the University of Colorado School of Medicine, and Brian Strahl, PhD, professor in the Department of Biochemistry & Biophysics at the University of North Carolina School of Medicine, published a breakthrough report in the journal Nature Chemical Biology describing the essential role of YEATS domain proteins in reading epigenetic marks that regulate gene expression, DNA damage response, and other vital DNA-dependent cellular processes. This newly discovered player in epigenetic regulation is closely related to known cancer promoters, including the bromodomain proteins, a handful of which are targeted in current human clinical trials.


Scientists from Penn Medicine and other institutions unlock a mystery about 'long non-coding RNAs'.
A new genetic clue discovered by a team co-led by a researcher at the Perelman School of Medicine at the University of Pennsylvania is shedding light on the functions of the mysterious "long non-coding RNAs" (lncRNAs). These molecules are transcribed from genes and are often abundant in cells, yet they do not code for proteins. Their functions have been almost entirely unknown--and in recent years have attracted much research and debate.

The pace of evolution is typically measured in millions of years, as random, individual mutations accumulate over generations, but researchers at Cornell and Bar-Ilan Universities have uncovered a new mechanism for mutation in primates that is rapid, coordinated, and aggressive. The discovery raises questions about the accuracy of using the more typical mutation process as an estimate to date when two species diverged, as well as the extent to which this and related enzymes played a role in primate evolution.

A novel investigation of how enzymatic reactions can direct the motion and organization of microcapsules may point toward a new theory of how protocells - the earliest biological cells - could have organized into colonies and thus, could have ultimately formed larger, differentiated structures.

According to epigenetics -- the study of inheritable changes in gene expression not directly coded in our DNA -- our life experiences may be passed on to our children and our children's children. Studies on survivors of traumatic events have suggested that exposure to stress may indeed have lasting effects on subsequent generations. But how exactly are these genetic "memories" passed on?


Tardigrades have not acquired a significant proportion of their DNA from other organisms, a new study shows.
Tardigrades, also known as moss piglets or water bears, are eight-legged microscopic animals that have long fascinated scientists for their ability to survive extremes of temperature, pressure, lack of oxygen, and even radiation exposure.


Kent Bradford, left, and Alfred Huo, seen here with a flowering lettuce plant, found that lettuce could be prevented from flowering by increasing the expression of a specific microRNA
Like most annuals, lettuce plants live out their lives in quiet, three-act dramas that follow the seasons. Seed dormancy gives way to germination; the young plant emerges and grows; and finally in the climax of flowering, a new generation of seeds is produced. It's remarkably predictable, but the genetics that coordinates these changes with environmental cues has not been well understood.


Space-filling model of Reb1 bound to DNA.
In a study published on 28 March 2016 in the Proceedings of the National Academy of Sciences, researchers at the Medical University of South Carolina (MUSC) and Virginia Commonwealth University have resolved the first protein structure in a family of proteins called transcription terminators. The crystal structure of the protein, called Reb1, provides insight into aging and cancer, according to Deepak Bastia, Ph.D., Endowed Chair for Biomedical Research in the MUSC Department of Biochemistry and Molecular Biology and co-senior author of the study.


This image shows TFIID (blue) as it contacts the DNA and recruits the polymerase (grey) for gene transcription. The start of the gene is shown with a flash of light.
Your DNA governs more than just what color your eyes are and whether you can curl your tongue. Your genes contain instructions for making all your proteins, which your cells constantly need to keep you alive. But some key aspects of how that process works at the molecular level have been a bit of a mystery--until now.

Think your DNA is all human? Think again. And a new discovery suggests it's even less human than scientists previously thought.


Every cell on the surface of this genetically engineered zebrafish expresses a unique combination of green, red and blue fluorescent proteins, resulting in over 70 different hues
Scientists can now watch how hundreds of individual cells work together to maintain and regenerate skin tissue, thanks to a genetically engineered line of technicolor zebrafish.

When we remember events which occurred recently, the hippocampus is activated. This area in the temporal lobe of the brain is a hub for learning and memory. But what happens, if we try to remember things that took place years or decades ago? Neuroscientists at the Ruhr-University Bochum and the Osaka University have been able to give some answers to this question. They reveal that the neural networks involved in retrieving very old memories are quite distinct from those used to remember recent events. The results of the study have now been published in the open source science journal eLIFE.

Plants grown in high-density or crowded populations often put more energy into growth and maintenance than reproduction. For example, flowering may be delayed as plants allocate resources to growing taller and escape competition for light. This sensitivity to crowding stress has been observed in some varieties of sweet corn, but other varieties show higher tolerance, producing high yields even in crowded conditions. A recent University of Illinois and USDA Agricultural Research Service study attempted to uncover the genetic mechanisms of crowding tolerance in sweet corn.


This is the cover of Protein & Cell.
The human brain is extremely complex, containing billions of neurons forming trillions of synapses where thoughts, behavior and emotion arise. However, when an individual is performing a particular task, not many but only a few neural circuits are in action. The enormous cellular heterogeneity of the brain structure has made dissections of the molecular basis for neural circuitry function particularly challenging, because previous studies on genetic and epigenetic profiling using a block of brain tissues simply do not have the sufficient precision and accuracy to correspond to the activities of a few activated circuitries in the brain.

Return to Biology News Net Homepage