Navigation Links
Ticking of cellular clock promotes seismic changes in the chromatin landscape associated with aging
Date:10/3/2010

LA JOLLA, CA-Like cats, human cells have a finite number of lives-once they divide a certain number of times (thankfully, more than nine) they change shape, slow their pace, and eventually stop dividing, a phenomenon called "cellular senescence".

Biologists know that a cellular clock composed of structures at the chromosome end known as telomeres records how many "lives" a cell has expended. Up to now, investigators have not yet defined how the clock's ticking signals the approach of cellular oblivion.

In a study published in the Oct. 3, 2010, issue of Nature Structural and Molecular Biology, a team led by Jan Karlseder, Ph.D., at the Salk Institute for Biological Studies reports that as cells count down to senescence and telomeres wear down, their DNA undergoes massive changes in the way it is packaged. These changes likely trigger what we call "aging".

"Prior to this study we knew that telomeres get shorter and shorter as a cell divides and that when they reach a critical length, cells stop dividing or die," said Karlseder, an associate professor in the Molecular and Cell Biology Laboratory. "Something must translate the local signal at chromosome ends into a huge signal felt throughout the nucleus. But there was a big gap in between."

Karlseder and postdoctoral fellow Roddy O'Sullivan, Ph.D., began to close the gap by comparing levels of proteins called histones in young cells-cells that had divided 30 times-with "late middle-aged" cells, which had divided 75 times and were on the downward slide to senescence, which occurs at 85 divisions. Histone proteins bind linear DNA strands and compress them into nuclear complexes, collectively referred to as chromatin.

Karlseder and O'Sullivan found that aging cells simply made less histone protein than do young cells. "We were surprised to find that histone levels decreased as cells aged," said O'Sullivan, the study's first author. "These proteins are required th
'/>"/>

Contact: Gina Kirchweger
kirchweger@salk.edu
858-453-410-01340
Salk Institute
Source:Eurekalert  

Page: 1 2 3

Related biology news :

1. Pitt/Iowa team finds cellular structural molecule can be toxic: Makes pneumonia worse
2. UCI-Scripps study links cellular motors to memory
3. Mount Sinai researchers discover new mechanism behind cellular energy conversion
4. SSRIs may pack more punch at the cellular level than believed
5. An IRCM researcher pinpoints the cellular mechanism responsible for modulating the permeability of blood vessels
6. A cellular housekeeper, and potential target of obesity drugs, caught in action
7. Origins of multicellularity: All in the family
8. Biologists identify a new clue into cellular aging
9. Researchers demystifying complex cellular communications hubs found in sensory neurons
10. Intracellular express -- why transport protein molecules have brakes
11. Cellular mechanical forces may initiate angiogenesis
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Ticking of cellular clock promotes seismic changes in the chromatin landscape associated with aging
(Date:11/18/2014)... The Parenteral Drug Association (PDA) today confirmed that seven officials ... least seven more will participate in the upcoming 2014 PDA ... Washington D.C. , Dec. 2-4. ... the regulatory agencies in the United States ... to help advance the use of metrics in the regulatory ...
(Date:11/15/2014)... , Nov. 13, 2014  While we may still be ... McCoy used in "Star Trek" to gain instant access to ... to work with smartphones and tablets for monitoring and measuring ... healthcare world. This may seem a tad Orwellian to some, ... adopt some of these technological opportunities into their healthcare regime. ...
(Date:11/11/2014)... CHICAGO , Nov. 11, 2014  Forensicon, Inc., ... eDiscovery firm, is pleased to announce the promotion of ... to Director of Digital Forensics. In Schiff,s new role ... out the team of digital forensics examiners and provide ... Photo - http://photos.prnewswire.com/prnh/20141110/157719 ...
Breaking Biology News(10 mins):FDA's Janet Woodcock, EMA's Emer Cooke Headline PDA Quality Metrics Conference 2Americans May Be Ready for a Brave New World of Healthcare 2Americans May Be Ready for a Brave New World of Healthcare 3Americans May Be Ready for a Brave New World of Healthcare 4Yaniv Schiff Promoted to Director of Digital Forensics at Forensicon, Inc. 2
... will conduct a series of scientific studies aimed at protecting and ... Estuary, Jobos Bay, La Parguera and other marine areas around Puerto ... it docks in San Juan on Feb. 12 and in Mayaguez ... to the U.S. Virgin Islands, where its crew will study coral ...
... New research has found that modern lifestyle habits may play ... tooth decay. A review of the scientific evidence ... fluoride toothpaste, good oral hygiene and health education, may override ... is published online in a Supplement to the journal ...
... (SIR) will present the latest research on treatments ... herniated disks; peripheral arterial disease (PAD) and related ... Annual Scientific Meeting March 7-12� at the San ... Highlights of embargoed key interventional radiology studies ...
Cached Biology News:EPA to study Puerto Rico waters and marine habitat 2Society of Interventional Radiology hosts 34th annual scientific meeting 2Society of Interventional Radiology hosts 34th annual scientific meeting 3Society of Interventional Radiology hosts 34th annual scientific meeting 4
(Date:12/19/2014)... CAMBRIDGE, MA (PRWEB) December 18, 2014 ... adults in the United States suffer from one or ... arthritis, asthma, or cancer. Medication can address some of ... to daily activities that many sufferers face. While implanted ... surgery and stimulate the whole nerve, which can induce ...
(Date:12/19/2014)... The empty capsules market is ... population and technological innovations in the empty capsules ... catalysing the growth of the empty capsules market. ... , Scope of Report , The report will ... entrants/smaller firms to gauge the pulse of the ...
(Date:12/19/2014)... -- Egenix, Inc. is pleased to announce that Lionel ... to succeed Donald Fresne ; Mr. Fresne has also ... member of the Board.  In recognition of the many contributions ... almost twenty years, the Board designated Mr. Fresne as Chairman ... a Search Committee to find a suitable replacement with Biotech ...
(Date:12/17/2014)... 2014 The Activated Carbon Manufacturing ... is why IBISWorld updated its original industry research report. ... from an intensified focus on environmental policy. Over the ... standards for power plants and a range of other ... Industry Analyst Sarah Kahn, “a range of downstream industrial ...
Breaking Biology Technology:Draper Wins GSK Funding for Smaller, Smarter Implantable Devices 2Empty Capsules Market Hit to Reach $1,820 Million by 2019 - New Research Report by MarketsandMarkets 2Empty Capsules Market Hit to Reach $1,820 Million by 2019 - New Research Report by MarketsandMarkets 3Empty Capsules Market Hit to Reach $1,820 Million by 2019 - New Research Report by MarketsandMarkets 4Activated Carbon Manufacturing in the US Industry Market Research Report Has Been Updated from IBISWorld 2Activated Carbon Manufacturing in the US Industry Market Research Report Has Been Updated from IBISWorld 3
... entered in favor of Guidant and its ... 2008 Boston,Scientific Corporation (NYSE: BSX ... Sarah Evans Barker, Indianapolis, dismissed proceedings,filed by ... of Guidant,s former directors and officers. Boston ...
... -- China,Technology Development Group Corporation (Nasdaq: CTDC; ... and renewable energy products and solutions,focusing on ... that the,Company attended the inauguration ceremony of ... Module manufacturing line in Changzhou, China,which is ...
... Pharmaceutical Companies Select Drug Model ... VIEW, Calif., April 2, 2008 ,Pharsight Corporation (Nasdaq: ... consulting, and regulatory services for optimizing clinical drug,development, ... have become customers for its Drug Model Explorer ...
Cached Biology Technology:District Judge Dismisses Shareholder Suit Related to Boston Scientific 2District Judge Dismisses Shareholder Suit Related to Boston Scientific 3CTDC Attends the Inauguration Ceremony of Thin Film A-Si Manufacturing Line in Changzhou, China 2CTDC Attends the Inauguration Ceremony of Thin Film A-Si Manufacturing Line in Changzhou, China 3Pharsight Signs Two New DMX(R) License Customers 2Pharsight Signs Two New DMX(R) License Customers 3