Tag Archives: nucleus

Locked RNA Editing Yields Odd Fly Behavior

At the level of proteins, organisms can adapt by editing their RNA — and an editor can even edit itself. Brown University scientists working with fruit flies found that “locking down” the self-editing process at two extremes created some strange behaviors. They also found that the process is significantly affected by temperature.

PROVIDENCE, R.I. [Brown University] — Because a function of RNA is to be translated as the genetic instructions for the protein-making machinery of cells, RNA editing is the body’s way of fine-tuning the proteins it produces, allowing us to adapt. The enzyme ADAR, which does this editing job in the nervous system of creatures ranging from mice to men, even edits itself. In a new study that examined the self-editing process and locked it down at two extremes in fruit flies, Brown University scientists found some surprising insights into how this “fine-tuning of the fine-tuner” happens, including bizarre behavioral effects that come about when the self-editor can’t edit. (more…)

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Protein ‘Jailbreak’ Helps Cancer Cells Live

Researchers at Brown University and Hasbro Children’s Hospital have traced the molecular interactions that allow the protein survivin to escape the nucleus of a breast cancer cell and prolong the cell’s life. The study may help in the development of better therapies and prognostics.

PROVIDENCE, R.I. [Brown University] — If the fight against breast cancer were a criminal investigation, then the proteins survivin, HDAC6, CBP, and CRM1 would be among the shadier figures. In that vein, a study to be published in the March 30 Journal of Biological Chemistry is the police report that reveals a key moment for keeping cancer cells alive: survivin’s jailbreak from the nucleus, aided and abetted by the other proteins. The research highlights that a protein’s location in a cell affects its impact on disease, and offers clear new leads for the investigation. (more…)

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A Whole New Meaning for Thinking on Your Feet

Smithsonian researchers report that the brains of tiny spiders are so large that they fill their body cavities and overflow into their legs. As part of ongoing research to understand how miniaturization affects brain size and behavior, researchers measured the central nervous systems of nine species of spiders, from rainforest giants to spiders smaller than the head of a pin. As the spiders get smaller, their brains get proportionally bigger, filling up more and more of their body cavities.

“The smaller the animal, the more it has to invest in its brain, which means even very tiny spiders are able to weave a web and perform other fairly complex behaviors,” said William Wcislo, staff scientist at the Smithsonian Tropical Research Institute in Panama. “We discovered that the central nervous systems of the smallest spiders fill up almost 80 percent of their total body cavity, including about 25 percent of their legs.” (more…)

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Anti-Helium Discovered in the Heart of STAR

*Berkeley Lab nuclear scientists join with their international colleagues in the latest record-breaking discovery at RHIC*

Eighteen examples of the heaviest antiparticle ever found, the nucleus of antihelium-4, have been made in the STAR experiment at RHIC, the Relativistic Heavy Ion Collider at the U.S. Department of Energy’s Brookhaven National Laboratory.

“The STAR experiment is uniquely capable of finding antihelium‑4,” says the STAR experiment’s spokesperson, Nu Xu, of the Nuclear Science Division (NSD) at Lawrence Berkeley National Laboratory (Berkeley Lab). “STAR already holds the record for massive antiparticles, last year having identified the anti-hypertriton, which contains three constituent antiparticles. With four antinucleons, antihelium-4 is produced at a rate a thousand times lower yet. To identify the 18 examples required sifting through the debris of a billion gold-gold collisions.” (more…)

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Berkeley Lab Researchers Illuminate Laminin’s Role in Cancer Formation

Laminin, long thought to be only a structural support protein in the microenvironment of breast and other epithelial tissue, is “famous” for its cross-like shape. However, laminin is far more than just a support player with a “pretty face.” Two studies led by one of the world’s foremost breast cancer scientists have shown how laminin plays a central role in the development of breast cancer, the second most leading cause of cancer death among women in the United States. In one study it was shown how laminin influences the genetic  information inside a cell’s nucleus. In the other study it was shown how destruction of laminin can play a detrimental role in the early stages of tumor development. (more…)

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NASA Releases Images of Man-Made Crater on Comet

PASADENA, Calif. — NASA’s Stardust spacecraft returned new images of a comet showing a scar resulting from the 2005 Deep Impact mission. The images also showed the comet has a fragile and weak nucleus.

The spacecraft made its closest approach to comet Tempel 1 on Monday, Feb. 14, at 8:40 p.m. PST (11:40 p.m. EST) at a distance of approximately 178 kilometers (111 miles). Stardust took 72 high-resolution images of the comet. It also accumulated 468 kilobytes of data about the dust in its coma, the cloud that is a comet’s atmosphere. The craft is on its second mission of exploration called Stardust-NExT, having completed its prime mission collecting cometary particles and returning them to Earth in 2006. (more…)

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Primordial Dry Ice Fuels Comet Jets

*Initial science results on comet released from University of Maryland, much more to come UMD scientists say.* 

 

Jets Galore. This enhanced image, one of the closest taken of comet Hartley 2. Image credit: University of Maryland

COLLEGE PARK, Md. – One of the biggest comet findings coming out of the amazing images and data taken by the University of Maryland-ledEPOXI mission as it zipped past comet Hartley 2 last week is that dry ice is the ‘jet’ fuel for this comet and perhaps many others. 

Images from the flyby show spectacular jets of gas and particles bursting from many distinct spots on the surface of the comet. This is the first time images of a comet have been sharp enough to allow scientists to link jets of dust and gas with specific surface features. Analysis of the spectral signatures of the materials coming from the jets shows primarily CO2 gas (carbon dioxide) and particles of dust and ice. 

“Previously it was thought that water vapor from water ice was the propulsive force behind jets of material coming off of the body, or nucleus, of the comet,” said University of Maryland Astronomy Professor Jessica Sunshine, who is deputy principal investigator for the EPOXI mission. “We now have unambiguous evidence that solar heating of subsurface frozen carbon dioxide (dry ice), directly to a gas, a process known as sublimation, is powering the many jets of material coming from the comet. This is a finding that only could have been made by traveling to a comet, because ground based telescopes can’t detect CO2 and current space telescopes aren’t tuned to look for this gas,” Sunshine said.  (more…)

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