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:4/20/2014)... known that people with Down syndrome have a heightened ... they haven,t been able to explain why. Now, ... a connection between the two conditions. , In a ... Genetics , the researchers track the genetic chain of ... to the cellular havoc that occurs in ALL. ...
(Date:4/18/2014)... X-ray crystallography and nuclear magnetic resonance imaging (NMR) to ... but such efforts have long been hampered by the ... molecule and often in ordered and crystalized form to ... peer into the structure of most molecules. , Harvard ... thing of the past. , A team of ...
(Date:4/18/2014)... adds a twist to the story of how barnyard chickens ... 21 in the journal Proceedings of the National Academy ... chickens that lived 200-2300 years ago in Europe, researchers report ... have looked far different from the chickens we know today. ... associate with modern domestic chickens -- such as their yellowish ...
Breaking Biology News(10 mins):Dana-Farber researchers uncover link between Down syndrome and leukemia 2Dana-Farber researchers uncover link between Down syndrome and leukemia 3MRI, on a molecular scale 2MRI, on a molecular scale 3Ancient DNA offers clues to how barnyard chickens came to be 2
... Solutions, a global life sciences technology solutions company ... to announce the latest release of ENLIGHTEN ... ENLIGHTEN system, which provides a proven, highly ... clinical trial management system (CTMS), has effectively supported ...
... University of Tennessee, Knoxville, researchers have found ... an estrogen-like compound in the environment which could ... adversely affect fish, plants and human health. Previously, ... these impacts. Theodore Henry, an adjunct ...
... is pleased to announce the recipients of the 2010 ... Advancement of Biotherapy. The 6 award winners were presented ... in Los Angeles; they are: David Armstrong, MD, DPM, ... MD, MPH; Kosta Mumcuoglu, PhD; and Aletha Tippett, MD, ...
Cached Biology News:MedNet Solutions Announces Significant Enhancements to ENLIGHTEN, Its Flagship EDC / eClinical Solution 2UT researchers link algae to harmful estrogen-like compound in water 2BTER Foundation announces winners of the William S. Baer Award 2BTER Foundation announces winners of the William S. Baer Award 3
(Date:1/14/2014)... January 14, 2014 Carahsoft and CDS ... January 23, 2014 at 2pm EST (11am PST), “Natural ... topic focuses on how technology can turn raw, heterogeneous ... for government agencies. The online webinar will last approximately ...
(Date:1/14/2014)... Jan. 14, 2014 The largest international professional ... plants and therapeutic derivatives thereof has endorsed an ... researchers about the challenges of adulterated herb and ... The Society for Medicinal Plant ...
(Date:1/14/2014)... Rockville, MD (PRWEB) January 14, 2014 ... dedicated to developing innovative information technology solutions for ... other health care stakeholders, announced today the signing ... the US Food and Drug Administration (FDA). ...
(Date:1/14/2014)... Independent publisher Bitingduck Press, with offices in Altadena ... ideas for 2014 in production and sales of interactive ... high-quality, low-cost, DRM-free ebooks and to use the sales ... first major development will be bookstore sales in local ...
Breaking Biology Technology:Webcast - Natural Language Processing: Converting Raw Data into Actionable Knowledge – Hosted by Carahsoft and CDS Federal Services 2World's Largest Group of Medicinal Plant Researchers Endorses ABC-AHP-NCNPR Botanical Adulterants Program 2World's Largest Group of Medicinal Plant Researchers Endorses ABC-AHP-NCNPR Botanical Adulterants Program 3World's Largest Group of Medicinal Plant Researchers Endorses ABC-AHP-NCNPR Botanical Adulterants Program 4World's Largest Group of Medicinal Plant Researchers Endorses ABC-AHP-NCNPR Botanical Adulterants Program 5World's Largest Group of Medicinal Plant Researchers Endorses ABC-AHP-NCNPR Botanical Adulterants Program 6World's Largest Group of Medicinal Plant Researchers Endorses ABC-AHP-NCNPR Botanical Adulterants Program 7World's Largest Group of Medicinal Plant Researchers Endorses ABC-AHP-NCNPR Botanical Adulterants Program 8Global Record Systems Announces Research Collaboration Agreement with FDA to Create a Novel “Big Data” Paradigm for Collection of Patient Safety and Outcomes Information 2Bitingduck Press Looks Forward to 2014 With Multimedia E-books 2
... is the First Latin American Country to ... Massachusetts, February 13, Shire plc (LSE: SHP)(NASDAQ: ... company, announced that ELAPRASE(R),(idursulfase), a human enzyme ... has been approved for commercial sale by ...
... 2008 Earnings Guidance and Introduces Q1 2008 Guidance, ... (Nasdaq:,CEPH) today reported 2007 sales of $1.727 billion, ... the company,s previously issued,guidance. Basic loss per common ... the previously announced settlement reserve, amortization expense,and certain ...
... Blood Bank,is proud to announce that two-time defending NASCAR ... "We,re honored to have this,NASCAR superstar and terrific person ... of CORD:USE. Jimmie Johnson joins CORD:USE as a,spokesperson to ... "I,m excited about telling people the benefits of ...
Cached Biology Technology:Shire's ELAPRASE(R) (idursulfase) Approved in Mexico for Treatment of Hunter Syndrome 2Shire's ELAPRASE(R) (idursulfase) Approved in Mexico for Treatment of Hunter Syndrome 3Shire's ELAPRASE(R) (idursulfase) Approved in Mexico for Treatment of Hunter Syndrome 4Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 2Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 3Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 4Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 5Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 6Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 7Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 8Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 9Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 10Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 11Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 12Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 13Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 14Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 15Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 16Cephalon's 2007 Results Exceed Full Year Sales and Earnings Guidance 17Two-time Defending NASCAR Sprint Cup Series Champion Jimmie Johnson Joins the Team at CORD:USE Cord Blood Bank to Help Win the Race for Life 2
... GRADE ,5-Bromo-4-chloro-3-indoxyl-beta-D-galactopyranoside C 14 H ... 6 ,M.W.= 408.63 ,Assay: Greater ... in DMF) ,Biological Activity: Blue color ... Analysis: Agrees with theoretical values ,Thin ...
BD IMagnet 1 each...
... A.P. Johnstone and M.W. Turner ... strategies and methods used in the ... of antibodies in immunoassays, the standardisation ... ELISA techniques including amplification systems, enzyme ...
MitoScreen (JC-1) Kit , 100 tests Consult technical datasheet for details....
Biology Products: