Navigation Links
Import of proteins into chloroplasts is differentially regulated by age
Date:10/30/2012

New research has found that the transport of proteins into chloroplasts in plants is differentially regulated by the age of the chloroplast; upturning the previously accepted notion that this process is age-independent or only globally up- or down- regulated for all proteins. The research, led by Dr. Hsou-min Li, a Research Fellow from the Institute of Molecular Biology, Academia Sinica of Taiwan, is published October 30 in the open access journal PLOS Biology.

It's long been known that gene expression changes with age, for example, some genes are expressed in young organisms, others in aged organisms. However, up until now, it has been generally believed that the protein-transport processes that take place inside a cell occur independently of the cell's age.

Dr. Li and colleagues investigated pea leaves of different ages and discovered that proteins imported into chloroplaststhe organelles in plant cells where photosynthesis occurscan be divided into three groups: one group prefers to be imported into very young chloroplasts, the second group has no special preference, and the third group prefer to be imported into older chloroplasts.

"Age-dependent regulation at the protein transport level had not been thoroughly investigated due to technical difficulties," Dr Li explained. "Pea seedlings offer an excellent model for such studies because each plant has leaves of different ages on a single stem and they are cheap to grow. Other scientists have taken advantage of this but at that time, they only had a very limited number of proteins to test. Now with data from genomic and proteomic analyses, we can test a lot more proteins and can show not only that the regulation exists, but also that every protein can be regulated differently."

After finding this novel regulation, Dr Li's group then attempted to find the signal that controls age selectivity. They found that, for each protein, the age-selective signal is located within the signal peptide that controls organelle import. They also identified a signal-peptide motif that is necessary for targeting proteins to older chloroplasts.

"We knew that signal peptides specify the organelle a protein is supposed to be targeted to, acting like address labels," said Dr Li. "When we found that they also contain the information for the age selectivity we observed, we decided to try to identify the "code" that instructs a protein to go to older chloroplasts first. The existence of such a code means that chloroplast signal peptides are not just address labels - they also contain information about "when" a protein should be delivered."

These findings may have implications for selectively targeting proteins into organelles of aging tissues, said Dr Li. "We believe similar kinds of regulation mechanisms may also exist for other organelles in other organisms, like humans. For example, there may be signal peptide motifs that will allow us to specifically target therapeutic proteins into mitochondria in aging cardiac tissues."


'/>"/>
Contact: Bryan Ghosh
bghosh@plos.org
44-122-344-2837
Public Library of Science
Source:Eurekalert

Related biology news :

1. An important breakthrough in the fight against muscular dystrophies
2. New research: Soluble corn fiber plays important role in gut health and calcium absorption
3. Reciprocity an important component of prosocial behavior
4. It must be important but what does it do? The strange case of UCP2
5. Differences between human twins at birth highlight importance of intrauterine environment
6. Large, medically important class of proteins starts to yield its secrets
7. University of Miami-led study finds winds played important role in keeping oil away from S. Fla.
8. Screening horticultural imports: New models assess plant risk through better analysis
9. Wildfire and an example of its important link to the ecosystem
10. Study sheds new light on importance of human breast milk ingredient
11. Overweight? New research explains how proper sleep is important for healthy weight
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/9/2016)... leader in attendance control systems is proud to announce the introduction of fingerprint attendance ... the right employees are actually signing in, and to even control the opening of ... ... ... Photo - ...
(Date:6/7/2016)... 2016  Syngrafii Inc. and San Antonio Credit ... includes integrating Syngrafii,s patented LongPen™ eSignature "Wet" solution ... will result in greater convenience for SACU members ... maintaining existing document workflow and compliance requirements. ... Highlights: ...
(Date:6/2/2016)... , June 2, 2016 The Department ... has awarded the 44 million US Dollar project, for the ... Vehicle Plates including Personalization, Enrolment, and IT Infrastructure , ... in the production and implementation of Identity Management Solutions. Numerous ... however Decatur was selected for the ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016   EpiBiome , ... secured $1 million in debt financing from Silicon Valley ... up automation and to advance its drug development efforts, ... new facility. "SVB has been an incredible ... the services a traditional bank would provide," said Dr. ...
(Date:6/23/2016)... ... ... In a new case report published today in STEM CELLS Translational Medicine, ... after being treated for breast cancer benefitted from an injection of stem cells derived ... debilitating, frequent side effect of cancer treatment. , Lymphedema refers to the ...
(Date:6/23/2016)... 23, 2016 Andrew ... http://doi.org/10.17925/OHR.2016.12.01.22 Published recently in ... journal from touchONCOLOGY, Andrew D Zelenetz , ... cancer care is placing an increasing burden on ... biologic therapies. With the patents on many biologics ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... quality, regulatory and technical consulting, provides a free webinar on Performing ... July 13, 2016 at 12pm CT at no charge. , Incomplete investigations are ...
Breaking Biology Technology: