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 The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

nachricht A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>