Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The difference between eye cells is…sumo?

11.03.2009
Johns Hopkins researchers discover critical switch in eye development

Researchers at the Johns Hopkins University School of Medicine and Washington University School of Medicine have identified a key to eye development — a protein that regulates how the light-sensing nerve cells in the retina form. While still far from the clinic, the latest results, published in the Jan. 29 issue of Neuron, could help scientists better understand how nerve cells develop.

"We've found a protein that seems to serve as a general switch for photoreceptor cell development," says Seth Blackshaw, Ph.D., an assistant professor in the Solomon H. Snyder Department of Neuroscience at Johns Hopkins. "This protein coordinates the activity of multiple proteins, acting like a conductor of an orchestra, instructing some factors to be more active and silencing others, and thus contributing to the development of light-sensitive cells of the eye."

Blackshaw's laboratory is trying to understand the steps necessary for developing light-sensitive eye cells to transition into one of two types: rod or cone cells. Any breakdown in the development of either type of cell can lead to impaired eyesight and, says Blackshaw, "the loss of cone cells in particular can lead to irreversible blindness." Rod cells help us see in dim or dark light, and cone cells help us see bright light and color.

The research team was interested in how other genes that are active in the developing retina can act to promote the development of rod cells while suppressing the development of cone cells. So they took a closer look at the candidate protein Pias3, short for protein inhibitor of activated Stat3. Pias3 was known to alter gene control in cells outside of the eye. In these cells, Pias3 doesn't directly turn genes on and off, but instead adds a chemical tag — through a process called SUMOylation — to other proteins that do switch genes on and off. And, since Pias3 also is found in developing rod and cone and no other cells in the eye, the team hypothesized that it might act to help these cells "decide" which type to become.

To determine whether Pias3 orchestrates rod cell development, the researchers used mice. First, they engineered mice to make more Pias3 than normal in the eye and counted rod and cone cells. Those eyes contained more rod cells than eyes from mice containing a normal amount of Pias3 protein. When they reduced the amount of Pias3 in developing mouse eyes, they found that the cells that might otherwise have been rod cells instead developed into conelike cells. So the team concluded that Pias3 promotes rod cell development and suppresses cone cell development.

Next they wanted to know if Pias3 works the same in eye cells as it does in other cells, through SUMOylation. The team altered the Pias3 protein to disrupt its SUMOylation activity. They found that eyes containing altered Pias3 did not develop the correct number of rod cells, suggesting that Pias3's SUMOylation activity was the key to its ability to promote rod and suppress cone cell development in the eye. The team also found that Pias3 SUMOylates a protein, Nr2e3, already known to influence rod and cone cell development, and showed that SUMOylation is critical for its ability to repress cone development.

Blackshaw hopes that his basic research results will contribute to translational and clinical research to generate more treatment options for blinding conditions such as macular degeneration, which arise from rod and cone cell death. "Future treatments might be designed to pharmacologically manipulate Pias3-dependent SUMOylation and potentially convert photoreceptors to a cone fate, thus providing a treatment for forms of inherited blindness that selectively result in the death of cone photoreceptors," says Blackshaw.

Audrey Huang | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Life Sciences:

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

nachricht Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>