HOME >> BIOLOGY >> NEWS
Scientists decipher "fail-safe" system that limits gene copying in cells

tinct controls have to be turned off simultaneously for cells to start replicating again. This is unlikely to happen by accident, so this multi-layered protection is virtually fail-safe. That's what you want when there is no room for error."

While multiple overlapping pathways are not thought to be an uncommon safeguard, few such systems have been clearly described, Li said.

In yeast, as in human cells, DNA replication is triggered in the nucleus when proteins known as replication factors position themselves at hundreds to thousands of pre-determined sites along the DNA molecule. Li's UCSF team knew that a specific set of proteins called kinases played a central role in preventing this critical process from starting more than once. But they did not know just how the kinases acted - whether, for example, they triggered the replication proteins into action or helped block their action. Nor, of course, did they know how many steps were involved.

The scientists found that the kinases act on at least three replication factors, knocking them out of commission in different ways. A kinase causes one replication factor called Mcm to get expelled from the nucleus; another, known as Cd6, is chemically degraded. A third replication protein, called ORC for "origin recognition complex," is de-activated by kinase through a still-unknown process.

Kinases are ubiquitous enzymes widely used in cells to regulate other proteins. In a step known as phosphorylation, they add a phosphate molecule to their target, changing its shape or signaling other proteins to degrade, relocate or modify it.

Only when the scientists managed to block the effects of kinases on all three replication proteins -Mcm, Cd6 and ORV - were they able to trigger DNA replication to re-start in the cell. But even this did not lead to a complete doubling of the cell's genome. About 50 percent of the genes were re-copied, the researchers report, suggesting that still more regulat
'"/>

Contact: Wallace Ravven
wravven@pubaff.ucsf.edu
415-476-2557
University of California - San Francisco
27-Jun-2001


Page: 1 2 3

Related biology news :

1. Scientists to prototype cyberinfrastructure for research and education access to ocean observatories
2. Scientists sequence genome of kind of organism central to biospheres carbon cycle
3. Scientists find nanowires capable of detecting individual viruses
4. Scientists discover potential new way to control drug-resistant bacteria
5. Scientists explore genome of methane-breathing microbe
6. Scientists decipher genetic code of biothreat pathogen
7. Stuck on you: Scientists lay bare secrets of bacterial attachment proteins
8. Scientists discover proteins involved in spread of HIV-1 infection
9. Scientists fear new Ebola outbreak may explain sudden gorilla disappearance
10. Scientists reinvent DNA as template to produce organic molecules
11. Scientists visualise cellular handmaiden that restores shape to proteins

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/14/2017)... (NYSE: IBM ) is introducing several innovative partner startups ... collaboration between startups and global businesses, taking place in ... nine startups will showcase the solutions they have built with ... France is one of the ... percent increase in the number of startups created between 2012 ...
(Date:5/16/2017)... 16, 2017   Bridge Patient Portal , ... MD EMR Systems , an electronic medical ... GE, have established a partnership to build an ... the GE Centricity™ products, including Centricity Practice Solution ... These new integrations will allow healthcare delivery ...
(Date:4/19/2017)... New York , April 19, 2017 ... competitive, as its vendor landscape is marked by the ... the market is however held by five major players ... Safran. Together these companies accounted for nearly 61% of ... of the leading companies in the global military biometrics ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... ... platform specifically designed for life science researchers to analyze and interpret datasets, ... Franklin, who made a major contribution to the discovery of the double-helix ...
(Date:10/11/2017)... ... ... Personal eye wash is a basic first aid supply for any work environment, but most ... you rinse first if a dangerous substance enters both eyes? It’s one less decision, and ... unique dual eye piece. , “Whether its dirt and debris, or an acid or alkali, ...
(Date:10/11/2017)... , Oct. 11, 2017  VMS BioMarketing, a leading ... a nationwide oncology Clinical Nurse Educator (CNE) network, which will ... need for communication among health care professionals to enhance the ... nurses, office staff, and other health care professionals to help ... breast cancer. ...
(Date:10/11/2017)... ... October 11, 2017 , ... ... implantation and pregnancy rates in frozen and fresh in vitro fertilization (IVF) ... and maternal age to IVF success. , After comparing the results from the ...
Breaking Biology Technology:
Cached News: