The prevailing view among scientists is that global climate change may prove beneficial to many farmers and foresters — at least in the short term. The logic is straightforward: Plants need atmospheric carbon dioxide to produce food, and by emitting more CO2 into the air, our cars and factories create new sources of plant nutrition that will cause some crops and trees to grow bigger and faster. But an unprecedented three-year experiment conducted at Stanford University is raising questions about that long-held assumption. Writing in the journal Science, researchers concluded that elevated atmospheric CO2 actually reduces plant growth when combined with other likely consequences of climate change — namely, higher temperatures, increased precipitation or increased nitrogen deposits in the soil.
The prospect of using bacteria to manufacture complex human proteins for use in therapeutic drugs is a step closer thanks to new research published today in Science. Researchers from Switzerland and the UK report they have engineered the bacterium Escherichia coli to carry a vital piece of cell machinery that adds sugar molecules to newly synthesized proteins by a process known as glycosylation. The finding opens up the possibility of producing complex human proteins such as Factor VIII and the hormone erythropoietin, which stimulates the production of red blood cells by stem cells in bone marrow. Both these proteins, which require the addition of sugar molecules to function properly, are currently produced by culturing mammalian cells, which can be a costly and technically difficult process.
Using advanced imaging technology and computational simulations, scientists have, for the first time, glimpsed the action of a cellular machine at work within living cells. The work puts forth a new concept of cellular machines as dynamic protein complexes that are continually building and rebuilding themselves within the cell, rather than the stable structures scientists have traditionally thought them to be.
Within the smoothly operating factory that is the cell, tiny molecular machines carry out their tasks with order and certainty. Or at least that’s what many scientists once believed. In a recent issue of Science, researchers report the first demonstration that bacterial cells intrinsically possess a significant degree of randomness or “noise.” More precisely, they show that key “gene-reading” machines may operate unpredictably, resulting in randomly fluctuating amounts of individual proteins.