Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study: Well-known protein helps stem cells become secretory cells

28.07.2005


Johns Hopkins researchers have discovered that a single protein regulates secretion levels in the fruit fly’s salivary gland and its skin-like outer layer.



Described in the May 15 issue of Development, the finding improves understanding of how cells become specialized for secretion, which is a critical ability of certain glands and cell types in organisms from insects to humans.

The researchers discovered that a protein called CrebA single-handedly controls the entire set of events leading to secretion in the fruit fly’s salivary gland and epidermis, its skin-like outer layer.


CrebA, or a closely related human gene, might play the same role in certain human cells, too, the researchers say.

In juvenile (type I) diabetes, for example, pancreatic cells that normally produce and secrete insulin don’t work, and stem cells might be able to help fix that problem, the researchers note. “The key is knowing how pancreatic cells know what hormones to produce and release, or how any gland does, and the new findings add to that knowledge,” says Deborah Andrew, Ph.D., professor of cell biology in Johns Hopkins’ Institute for Basic Biomedical Sciences.

Curiosity brought Andrew and Elliott Abrams, then a graduate student, to focus on secretion in the salivary gland, the largest glandular organ in the fruit fly embryo, approximately six years ago. In humans and in fruit flies, the gland secretes saliva, a fluid containing water, mucus, electrolytes, and food-dissolving enzymes, into the mouth, and is important to the digestive system.

In their new experiments, the researchers looked at the expression of 34 secretory genes in a normal fruit fly embryo to see which genes were turned on when. All 34 genes were expressed at high levels in the early salivary gland, they found. According to Andrew, “This suggests the salivary gland becomes programmed for secretion because all the components required to allow secretion to occur are ‘turned on’ very early in development.”

In order for any gene’s instructions to be used to make a protein, the process of reading the instructions is jump-started by proteins called transcription factors. In the salivary gland, the researchers found two of these proteins that controlled secretory gene expression in the salivary gland: CrebA (Cyclic-AMP response element binding protein A) and Fkh (Fork head).

CrebA is required for the expression of the secretory genes throughout development, while Fkh appears to be required only in later embryonic stages. The group has shown that Fkh is required to maintain expression of CrebA in the salivary gland. “CrebA is the more immediate factor involved in keeping secretory genes expressed at high levels, and Fork head acts through it,” said Andrew.

CrebA’s role in the fruit fly’s epidermis gives it secretion-promoting powers there as well, the researchers note. In fruit flies, epidermal cells secrete the cuticle, a protective covering for the organism.

“Our findings suggest that this single transcription factor directly determines the amount of secretory activity in a given cell type,” said Andrew.

Funding for the study was provided by the National Institutes of Health.
Development 132, 2743-2758 (2005)

Joanna Downer | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Studies and Analyses:

nachricht Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>