Featured Research

from universities, journals, and other organizations

Tidying Up Transcription Factors

Date:
February 1, 2002
Source:
Rockefeller University
Summary:
Fifty years ago, in the early days of biology, so little was known about the cell that all of the proteins outside of its nucleus were grouped into one big "cytoplasmic soup." Now, as the list of known cellular ingredients continues to expand beyond the capacity of any recipe card, two Rockefeller University scientists are taking a step back to ask whether there might be a better way to organize the current thinking about a particularly important class of proteins inherent to all living cells.

Fifty years ago, in the early days of biology, so little was known about the cell that all of the proteins outside of its nucleus were grouped into one big "cytoplasmic soup." Now, as the list of known cellular ingredients continues to expand beyond the capacity of any recipe card, two Rockefeller University scientists are taking a step back to ask whether there might be a better way to organize the current thinking about a particularly important class of proteins inherent to all living cells.

In the Feb. 1 issue of Science, James E. Darnell, Jr., M.D, and Ali H. Brivanlou, Ph.D., propose a reclassification of all known transcription factors - an essential group of over 2000 proteins responsible for turning genes "on" or "off." Their proposed schema is the first-ever ordering of transcription factors based solely upon the role these molecules play in the cell.

"Our aim in this paper is to provide a framework with sufficiently few functional categories of transcription factors so that students and researchers have some chance to remember all the important groups. We also believe this teaching aid is based on sound cell physiologic principles," says Darnell, head of the Laboratory of Molecular Cell Biology at Rockefeller University and co-author of the popular textbook, "Molecular Cell Biology."

"We need a global perspective such as this in order to form new ideas about how cells deal with the necessity to change transcription rates," says Brivanlou, head of the Laboratory of Molecular Vertebrate Embryology at Rockefeller.

Transcription is the process by which cells "read" their genetic instructions: DNA is "transcribed" into RNA, which is then converted into protein. Specific proteins in the cell called transcription factors control which genes are read and which ones are silenced, thereby dictating everything that goes on in a given cell at any moment. Well-studied transcription factors include p53 and the Smad and STAT proteins, all of which play a major role in many cancers.

Because transcription goes awry in many diseases, including cancer and viral infections such as HIV, a better understanding of how cells "read" genetic instructions may lead to new drug therapies for these diseases.

Previously, transcription factors were grouped by scientists according primarily to their physical structure as determined through X-ray crystallography. However, all of the proteins in one structural group don't necessarily operate in similar fashion physiologically.

"Jim Darnell and I realized that it makes more sense to think about these proteins in terms of their behavior instead of their structure," says Brivanlou.

The two scientists first began discussing this issue with students during a course Darnell was teaching Rockefeller University. The title of the course was "gene expression" and included discussions of the various ways in which the cell receives instructions from the outside and then responds to these signals by altering the production of specific proteins, or, in scientific terms, the "expression" of certain genes. These signals include primarily hormones (e.g., estrogens) and small proteins (e.g., growth hormone). Transcription factors are the mediators of these signals and ultimately govern which genes are expressed.

Darnell and Brivanlou realized that by grouping transcription factors according to how they are signaled or controlled, they could more readily recognize global patterns, such as evolutionary relationships between groups of transcription factors.

Yet the new classification is not meant to be an end in itself, according to the scientists. "This is not a Unified Law of Transcription Factors," jokes Brivanlou.

Darnell adds, "We know that some of these groupings may be controversial, but we think there are good reasons to classify groups the way we have. For example, all of the factors that respond to extracellular protein signals are very disparate in their internal activation pathways but all share a global design: cell surface stimulation by an extracellular protein that activates a latent cytoplasmic factor which upon activation enters the nucleus to function in activating gene transcription."

The researchers hope the paper will foster vigorous discussions about how to best organize these important proteins and ultimately lead to new and important concepts about the workings of the cell.

The Darnell and Brivanlou laboratories are supported largely by the National Institutes of Health.

John D. Rockefeller founded Rockefeller University in 1901 as The Rockefeller Institute for Medical Research. Rockefeller scientists have made significant achievements, including the discovery that DNA is the carrier of genetic information. The University has ties to 21 Nobel laureates, six of which are on campus. Rockefeller University scientists have received this award for two consecutive years: neurobiologist Paul Greengard, Ph.D., in 2000 and cell biologist Gόnter Blobel, M.D., Ph.D., in 1999, both in Physiology or Medicine. At present, 33 faculty are elected members of the U.S. National Academy of Sciences. Celebrating its Centennial anniversary in 2001, Rockefeller - the nation's first biomedical research center - continues to lead the field in both scientific inquiry and the development of tomorrow's scientists.


Story Source:

The above story is based on materials provided by Rockefeller University. Note: Materials may be edited for content and length.


Cite This Page:

Rockefeller University. "Tidying Up Transcription Factors." ScienceDaily. ScienceDaily, 1 February 2002. <www.sciencedaily.com/releases/2002/02/020201075255.htm>.
Rockefeller University. (2002, February 1). Tidying Up Transcription Factors. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2002/02/020201075255.htm
Rockefeller University. "Tidying Up Transcription Factors." ScienceDaily. www.sciencedaily.com/releases/2002/02/020201075255.htm (accessed July 30, 2014).

Share This




More Plants & Animals News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) — Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) — At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Raw: Otters Enjoy Water Slides at Japan Zoo

Raw: Otters Enjoy Water Slides at Japan Zoo

AP (July 30, 2014) — River otters were hitting the water slides to beat the summer heatwave on Wednesday at Ichikawa City's Zoological and Botanical Garden. (July 30) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins