Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Unravel Clue in Cortisol Production

26.04.2007
When a person’s under stress or injured, the adrenal gland releases cortisol to help restore the body’s functions to normal. But the hormone’s effects are many and varied, lowering the activity of the immune system, helping create memories with short-term exposure, while impairing learning if there’s too much for too long. Given the variety of its effects,understanding how cortisol is made is essential to producing medications that can alter its production.

Scientists at the Georgia Institute of Technology have discovered an important step in cortisol production, finding that although the output of the hormone is continuous, the molecular production is cyclic in nature – involving a rhythmic binding and unbinding of a protein essential to its production. The research, which increases understanding of how the brain and the endocrine system work together to regulate health, appears in the February issue of the journal Molecular Endocrinology.

Turning cholesterol into the stress hormone cortisol involves many reactions and begins when the hypothalamus sends a signal to the adrenal glands. Proteins then flood into the nucleus to bind to the DNA, creating the gene CYP 17. What happens next is well understood; CYP 17, along with a battery of other enzymes, transforms cholesterol into cortisol. But what isn’t understood is how this protein binding creates CYP 17, or which proteins are important. So, graduate students Eric Dammer and Adam Leon, along with Marion Sewer, assistant professor in Georgia Tech’s School of Biology, decided to model the events that occur after the adrenal gland receives the signal.

One of the things the signal does is cause adrenal cells to increase their production of cyclic AMP (cAMP), a chemical that encourages proteins to interact. So they began by causing the cells to make more cAMP. Then as the proteins assembled on the DNA, they tested the cells at different intervals in order to get a snapshot of which proteins were interacting, both with each other and the DNA and in which order this occurred. Then they mutated the proteins to stop them from fulfilling their roles.

... more about:
»CYP »Cortisol »DNA »SF-1 »adrenal »gland

"One of the best ways to try and figure out the function of a protein or a gene is to get rid of it or mutate it so that it’s not acting normally. Then you compare it with one that is acting normally,” said Sewer.

In this study, they focused on a protein known as steriodogenic factor 1 (SF-1), which is essential for making all steroid hormones. Researchers were interested in discovering what events have to occur in order for SF-1 to bind to DNA.

The first thing they found was that because DNA is so tightly packed in the nucleus, SF-1 can’t bind to it until it’s unpacked by a group of proteins. Once that happens, SF-1 binds to the genes, beginning the process that makes CYP 17 and ultimately cortisol. But it’s not a continuous process, they found.

"Once SF-1 binds, it leaves. A few minutes later other proteins come in and condense the DNA,” said Sewer. “After that SF-1 binds again, then leaves, and the proteins cause the DNA to contract again.”

This cycle goes on as long as the adrenal gland is receiving the signal.

"Even though you get a sustained production of cortisol, the actual molecular events that happen in the nucleus are dynamic,” said Sewer. “It’s an extremely complex series of events that starts within minutes of the adrenal gland receiving the signal. Without all these transient binding events, the adrenal gland fails to produce optimal levels of cortisol.”

Next the team will investigate how small molecules – ligands – regulate cortisol production by binding to SF-1 and controlling the receptor’s ability to bind to DNA.

This research was supported by the National Institutes of Health, the National Science Foundation and the Georgia Cancer Coalition.

David Terraso | EurekAlert!
Further information:
http://www.gatech.edu

Further reports about: CYP Cortisol DNA SF-1 adrenal gland

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>