Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists work to break cellular code

07.11.2003


Despite the rich knowledge scientists now have of the genes that constitute the human genome, researchers have yet to unravel the precise choreography by which they work – or malfunction – together in the cell in response to triggers from the outside world.



"There is a code we need to understand to determine what happens to a cell under many different conditions, and ultimately to make predictions of how an entire genome is regulated," explains Julia Zeitlinger, a postdoctoral associate at Whitehead Institute for Biomedical Research.

Key to cracking this code, she says, is a set of proteins called transcription factors, which bind to specific genes to produce proteins. Akin to computer programs that return different results depending on the input data, transcription factors can carry out multiple functions in the cell in response to distinct stimuli.


For example, expose a yeast transcription factor called Ste12 to a certain pheromone from a potential mating partner, and it induces a mating response. But starve the yeast for nutrients, and the same transcription factor provokes filamentation – the yeast begins to sprout numerous threadlike strands.

Pinpointing the mechanism that makes transcription factors such as Ste12 respond differently under different environmental inputs could enable scientists to better predict cellular behavior and disease pathology.

In a study published earlier this year in the journal Cell, Zeitlinger and colleagues at Whitehead discovered that when a multipurpose transcription factor is exposed to a particular environmental condition, it directly orchestrates a global change throughout the genome in binding sites involved in the cellular behavior induced by that condition.

The team monitored all binding sites of the transcription factor Ste12 in yeast while exposing the genome to the pheromone that induces mating and to butanol, an alcohol that mimics the conditions that promote filamentation. They used a technique called genome-wide location analysis, a process pioneered by Whitehead Member Richard Young that uses DNA microarrays to enable rapid analysis of protein interaction with the DNA of an entire genome.

"When we profiled the binding sites of Ste12 under the two developmental conditions, we found that Ste12 indeed undergoes the predicted global switch in binding," recalls Zeitlinger, who works in Young’s lab and collaborates with scientists at MIT’s The Broad Institute. The researchers found that this transcription factor, rather than activating a chain reaction of other transcription factors in the cellular network, directly determines which genes are activated under each condition.

Zeitlinger plans to investigate if this mechanism occurs generally in yeast and higher organisms, work that ultimately could help physicians better understand, diagnose and disrupt certain diseases at the cellular level.

"Ste12 is able to undergo the switch in binding because of its cooperative interaction with another transcription factor, Tec1," Zeitlinger says. "My hypothesis is that there are different types of cooperative interactions between transcription factors. By defining them and understanding how they work, I hope to construct a grammar to the regulatory code. This will help to make predictions of cellular behavior based on DNA sequence."

Kelli Whitlock | EurekAlert!
Further information:
http://www.wi.mit.edu/home.html

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 >>>