Featured Research

from universities, journals, and other organizations

Researchers Build Diagram Of Cell Cycle Clock

Date:
October 3, 2001
Source:
Whitehead Institute For Biomedical Research
Summary:
For the first time, researchers at the Whitehead Institute have mapped the complete circuit of one of life's most fundamental processes—the cell cycle, which tells cells when to divide. This network diagram describes the genetic switches and connections that form the circuit common to a process found in all living organisms, from bacteria to human beings.

For the first time, researchers at the Whitehead Institute have mapped the complete circuit of one of life's most fundamental processes—the cell cycle, which tells cells when to divide. This network diagram describes the genetic switches and connections that form the circuit common to a process found in all living organisms, from bacteria to human beings. The findings were published in the September 21 issue of Cell by Whitehead Member Richard Young and his colleagues.

"This study is important because it shows for the first time that we can use a technique called genome-wide location analysis to map the circuitry underlying many fundamental life processes," says Young, whose lab developed this technique six months ago. "We now have a technique to connect the control switches that make up the network for any living process you can think of—memory, digestion, aging. In turn, this will shed light on many diseases, which are basically breaks in the circuit."

Mapping the circuits of fundamental processes in health and disease is one of the next steps of the Human Genome Project, which identified the genetic parts list for these processes but not the connections that make life run. Scientists agree that deciphering these circuits is important, but this is the first study to show that it can be done, and therefore provides reason for excitement in the scientific community, say the authors.

The cell cycle is one of life's most important processes, dictating cell division in virtually all aspects of life. Understanding the fundamental cycle of how a cell knows when to divide is key to finding out what goes wrong in diseases such as cancer, where cells divide uncontrollably.

During cell division several events have to occur in an orderly sequence—for instance, the chromosomes of the cell duplicate, the two sets of chromosomes segregate, and the cell splits into two daughter cells. Though scientists knew about the separate stages of the cell cycle, they didn’t fully understand how the switches for each step were connected to the next one or what controlled them. To understand the process, the Young lab focused on nine master switches that are involved in the baker’s yeast cell cycle.

Itamar Simon, a postdoctoral fellow in the Young lab and first author on the Cell paper, mapped how the cell cycle in yeast is controlled by the nine proteins called transcriptional activators. These proteins bind to genes to turn them on, so the corresponding proteins necessary for a certain cell cycle stage are produced.

Simon found that a transcriptional activator from one stage of the cell cycle also activates transcriptional activators in the next stage of the cell cycle—creating a series of switches connected in a circular network. "It makes elegant sense that the cell cycle is controlled through a circular network, but that wasn’t anticipated. We now see that the network that controls the cell cycle is itself a cycle of regulators regulating regulators. Until recently, we didn’t have a technique to probe this kind of problem," says Simon.

Simon used a technique developed in the Young lab, which was published in Science last December. The technique involves first fixing DNA-binding proteins in living cells to their binding sites using chemical cross-linking methods and then breaking open the cells to create a molecular soup of DNA-protein complexes. Specific antibodies coupled with magnetic beads are then used to fish out DNA fragments cross-linked to the proteins. This provides researchers with a population of DNA-protein complexes, and unhooking the cross-linked DNA from the protein leaves them with DNA fragments that bind to proteins of interest. The researchers then label these fragments with fluorescent dye and hybridize them to a DNA array containing genomic DNA from yeast to reveal their identity.

This technique provides direct information that can’t be deduced from DNA arrays, which are useful in determining a cell’s expression profile (a snapshot of which genes are turned on and off in a cell) at a moment in time. A change in the cell’s environment can trigger a cascade of changes inside the cell, all of which can be captured in another snapshot. Though this provides information about what is going on in cell from one moment to the next, it doesn’t tell what is regulating the changes.

Understanding how biological processes are regulated on a genomic scale is a fundamental problem for the coming decades. "The pharmaceutical industry is based on therapeutics developed for correcting faulty protein products, which result from breakdowns in metabolic pathways. A new area of pharmaceutical industry will develop based on drugs targeting breakdowns in genome regulatory networks. Perhaps we can correct some problems even before a faulty protein is produced," predicts Young.


Story Source:

The above story is based on materials provided by Whitehead Institute For Biomedical Research. Note: Materials may be edited for content and length.


Cite This Page:

Whitehead Institute For Biomedical Research. "Researchers Build Diagram Of Cell Cycle Clock." ScienceDaily. ScienceDaily, 3 October 2001. <www.sciencedaily.com/releases/2001/10/011003064303.htm>.
Whitehead Institute For Biomedical Research. (2001, October 3). Researchers Build Diagram Of Cell Cycle Clock. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2001/10/011003064303.htm
Whitehead Institute For Biomedical Research. "Researchers Build Diagram Of Cell Cycle Clock." ScienceDaily. www.sciencedaily.com/releases/2001/10/011003064303.htm (accessed July 24, 2014).

Share This




More Matter & Energy News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com
Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Car Market on the Rebound?

Europe's Car Market on the Rebound?

Reuters - Business Video Online (July 23, 2014) Daimler kicks off a round of second-quarter earnings results from Europe's top carmakers with a healthy set of numbers - prompting hopes that stronger sales in Europe will counter weakness in emerging markets. Hayley Platt reports. Video provided by Reuters
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