Genetics & Molecular Biology

When a large protein unfolds in a cell, it slows down and can get stuck in traffic. University of Illinois chemists now can watch the way the unfolded protein diffuses, which could provide great insight into protein-misfolding diseases such as Alzheimer's and Huntington's.

Researchers have hypothesized that an unfolded protein moves more slowly through the cell, because it would be a big, stringy mess rather than a tightly wrapped package. The team devised a way to measure how diffusion slows down when a protein unfolds using a fluorescence microscope, then used three-dimensional diffusion models to connect the protein's unfolding to its motion. 

Macrophages sweep up cellular debris and pathogens in order to thwart infection - sometimes even before the white blood cells, which are designed for that task. 

Neutrophils, white blood cells, are "first responders" that are attracted to wounds by signaling molecules called reactive oxygen species (ROS) that activate a protein kinase. When neutrophils finish their work, inflammation is partly resolved through apoptosis, or cell suicide, and then macrophages arrive to clean up the infection.

But neutrophils can also elect to leave wounded tissue in a process known as reverse migration. Whether macrophages promote this mode of inflammation resolution is unclear. 

Alzheimer's disease progresses inside the brain as deposits of the toxic protein amyloid-beta (Aβ),overwhelm neurons. A side effect of accumulating Aβ in neurons is the fragmentation of the Golgi apparatus, the part of the cell involved in packaging and sorting protein cargo including the precursor of Aβ. Or it may be the other way around and loss of Golgi function is a driving force behind Alzheimer's.

Yanzhuang Wang, Gunjan Joshi, and colleagues at the University of Michigan, Ann Arbor, set out to uncover the mechanism damaging the Golgi using a transgenic mouse and tissue culture models of 
Alzheimer's disease
to look at what was going on. 

Scientists have identified four new genes associated with a severe food allergy called eosinophilic esophagitis (EoE), which has only recently been recognized as a distinct condition. Its hallmark is inflammation and painful swelling in the esophagus, along with high levels of immune cells called eosinophils. It can affect people of any age, but is more common among young men who have a history of other allergic diseases such as asthma and eczema. 

 Everyone inherits two copies of most genes, one copy from each parent. In a recent study, researchers found in a rare mutation, people with one inactive copy of the gene NPC1L1 appeared to be protected against high LDL cholesterol, commonly called the "bad" cholesterol, and coronary heart disease, a narrowing of the heart's arteries that can lead to heart attacks. 

This mutation meant a 50 percent reduction in the risk of heart attack, at least epidemiologically, according to the paper
in The New England Journal of Medicine. NPC1L1 is of interest because it is the target of the drug ezetimibe, often prescribed to lower cholesterol.

The yellow fever mosquito sustains its taste for human blood thanks to a genetic tweak that makes it more sensitive to human odor, according to a paper in Nature. They have a version of an odor-detecting gene in its antennae that is highly attuned to sulcatone, a compound prevalent in human odor.

The gene, AaegOr4, is more abundant and more sensitive in the human-preferring "domestic" form of the yellow fever mosquito than in its ancestral "forest" form that prefers the blood of non-human animals. 

When a cell divides, it passes through a sequence of complex events and mitochondria, the organelles called the power plants of the cell, are the main source of energy for these processes: They convert food into energy the cell can use.

Freiburg biochemists Dr. Angelika Harbauer and professor Chris Meisinger led a team that have discovered a signaling path that links these two key tasks, cell division and energy conversion. .

Let’s talk about gastrulation. For those unfamiliar with the term, it’s not as disgusting as it sounds. Gastrulation is a process in early embryonic development which leads to the generation of the three germ-layer tissues- ectoderm, endoderm, and mesoderm- from which all other tissue-types in the body are erived. 

The early (amniote) embryo coverts from a bilaminar structure of epithelial tissue plus and extra-embryonic layer, to a trilamiarone. A second function of gastrulation is that it defines the anterior-posterior body axis for the first time. In other words, it begins to distinguish the head end of the embryo from the tail end- this is pretty important if you want all your bits and pieces in the right place later on! 

Heart attacks are often caused by conditions that affect electrical signaling in the heart. Genetic studies have linked two of these conditions, long QT syndrome and Brugada syndrome, to mutations in the sodium channels that let sodium ions into cells in response to electrical signals.  
A multidisciplinary team has been tracking the complex of proteins thought to be at fault in some cases of sudden cardiac death and now they have finally captured images of the complex. Those images reveal the connection between some genetic mutations and electrical abnormalities of the heart and provide a starting point for designing therapies.