Microbiology

To function, each living cell needs both to build new and to degrade old or damaged proteins. To accomplish that, a number of intracellular systems work in concert to keep the cell healthy and from clogging up with damaged proteins. When proteins or peptides mutate, they can present major problems to the clearing up of the intracellular environment. In Huntington's disease (HD) the disease provoking mutation in the huntingtin gene eventually causes the cell to build up intranuclear and cellular inclusions of protein-aggregates, made up primarily of huntingtin. One cellular organelle with a…

An artificial nose could be a real benefit at times: this kind of biosensor could sniff out poisons, explosives or drugs, for instance. Researchers at the Max Planck Institute for Polymer Research and the Max Planck Institute of Biochemistry recently revealed a technique for integrating membrane proteins into artificial structures. Membrane proteins have several important functions in the cell, one of which is to act as receptors, passing on signals from molecules in the air, for example, to the cell interior. They are thus ideal biosensors, but until now were difficult to access in the lab…

Human nerve stem cells transplanted into rats' damaged spinal cords have survived, grown and in some cases connected with the rats' own spinal cord cells in a Johns Hopkins laboratory, overturning the long-held notion that spinal cords won't allow nerve repair. A report on the experiments will be published online this week at PLoS Medicine and "establishes a new doctrine for regenerative neuroscience," says Vassilis Koliatsos, M.D., associate professor of neuropathology at Johns Hopkins. "The spinal cord, a part of the nervous system that is thought of as incapable of repairing itself, can…

During development and during pathological processes in the adult, cells are constantly changing their function. One, well-characterized, cellular transition that occurs during development, as well as during wound healing, tissue fibrosis, and tumor metastasis, is the transition from an epithelial cell to a mesenchymal cell (often a fibroblast). This change in cell type and function is known as epithelial-mesenchymal transition (EMT) and it has been shown that a protein known as FSP1 is important for this transition. However, the proteins that direct the change in the pattern of genes…

Thanks to Buck and Axel and colleagues, most neuroscientists are aware of the precise topographical map of the mouse olfactory nerve projection in which each olfactory sensory neuron (OSN) expresses a single odorant receptor (OR), and OSNs expressing a given OR converge on a set of glomeruli in the olfactory bulb. This week, Sato et al. mapped the zebrafish axonal projection using a bacterial artificial chromosome transgene. The transgene contained a cluster of 16 OR genes, two of which (OR111–7 and OR103–1) were replaced with yellow and cyan membrane-targeted reporters. Distinct sets of…

A breakthrough in understanding the way atoms move across cell membranes in the human body could pave the way for the development of new treatments for inflammatory diseases such as rheumatoid arthritis. Scientists at the University of Leeds have identified a previously unknown natural mechanism that opens ion channels – proteins at the cell surface that act as doorways into and out of cells – through the naturally occurring protein thioredoxin. Ion channels allow movement of ions - electrically charged atoms - across the cell membrane to carry out various functions such as pain transmission…