Navigation Links
IU-led team uncovers process for chameleon-like changes in world's most abundant phytoplankton
Date:11/26/2012

An international team of biologists led by Indiana University's David M. Kehoe has identified both the enzyme and molecular mechanism critical for controlling a chameleon-like process that allows one of the world's most abundant ocean phytoplankton, once known as blue-green algae, to maximize light harvesting for photosynthesis.

Responsible for contributing about 20 percent of the total oxygen production on the planet, the cyanobacteria Synechococcus uses its own unique form of a sophisticated response called chromatic acclimation to fine tune the absorption properties of its photosynthetic antenna complexes to the predominant ambient light color. The researchers identified and characterized an enzyme, MpeZ, that plays a pivotal role in the mechanism that allows two different water-soluble proteins in Synechococcus -- phycoerythrin I and II -- to alter their pigmentation in order to maximize photon capture for photosynthesis.

Scientists want to understand how cyanobacteria optimize their photosynthetic activities in different light conditions to gain a better appreciation of how human activities affect the phytoplankton's ability to produce oxygen and uptake the greenhouse gas carbon dioxide, which they consume in order to grow. Science and industry also use the pigment-protein complex phycoerythrin for fluorescent imaging and as fluorescent markers in biotechnology and health care applications.

"We now have the ability to attach a novel chromophore, part of a molecule responsible for its color, to phycoerythrin, which provides a new chromophore-protein combination that absorbs and fluoresces at a wavelength that is not currently commercially available," said Kehoe, a professor in the IU Bloomington College of Arts and Sciences' Department of Biology. "Our results suggest that this new chromoprotein is brighter and more stable than most on the market today."

Kehoe also noted IU has begun the process of filing a patent on the invention.

The team found that the gene encoding the MpeZ enzyme is activated in blue light. Once produced, MpeZ then binds to antenna proteins containing pigments that normally catch green light and attaches an alternative chromophore that allows the antennae to capture blue light. The specific mechanism, called type IV chromatic acclimation, involves replacing three molecules of the green light-absorbing chromophore with an equal number of blue light-absorbing chromophore. This color-shifting is reversible and is controlled by the ratio of blue to green light in the environment.

"These 'chromatic adapters' are true chameleons that can efficiently live in green coastal waters as well as in blue offshore waters by modifying their pigmentation," Kehoe said. "Synechococcus cells maintained in blue light harvest preferentially blue light, while cells grown in green light harvest more green."

"A phycoerythrin-specific bilin lyase-isomerase controls blue-green chromatic acclimation in marine Synechococcus" was published online in the Early Edition of Proceedings of the National Academy of Sciences. Co-authors with Kehoe, also affiliated with IU Bloomington's Indiana Molecular Biology Institute, were IU Ph.D. student Animesh Shukla; Avijit Biswas and Wendy M. Schluchter of the University of New Orleans; Nicolas Blot of Universit Pierre et Marie Curie - Paris 06, the Centre National de la Recherche Scientifique and Clermont Universit in France; Frederic Partensky and Laurence Garczarek of Universit Pierre et Marie Curie - Paris 06 and the Centre National de la Recherche Scientifique; IU Bloomington Department of Chemistry METACyt Biochemical Analysis Center mass spectrometry facility manager and assistant scientist Jonathan A. Karty and assistant scientist Loubna A. Hammad; and former IU biology graduate student Andrian Gutu, now of Harvard University.


'/>"/>

Contact: Steve Chaplin
stjchap@iu.edu
812-856-1896
Indiana University
Source:Eurekalert  

Related biology news :

1. Rising carbon dioxide in atmosphere also speeds carbon loss from forest soils, IU-led research finds
2. UCI-led study uncovers how Salmonella avoids the bodys immune response
3. International team uncovers new genes that shape brain size, intelligence
4. Screening technique uncovers 5 new plant activator compounds
5. Study shows unified process of evolution in bacteria and sexual eukaryotes
6. KIT: Processes at the surface of catalysts
7. Antioxidant may disrupt Alzheimers disease process
8. Study resolves debate on human cell shut-down process
9. ORNL process improves catalytic rate of enzymes by 3,000 percent
10. Thomson Reuters Launches Life Sciences Partner Ecosystem to Drive Collaborative R&D Drug Processes
11. Scientists discover enzyme that could slow part of the aging process in astronauts -- and the elderly
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
IU-led team uncovers process for chameleon-like changes in world's most abundant phytoplankton
(Date:2/1/2016)... 1, 2016 Rising sales of ... global touchfree intuitive gesture control market size ... sales of consumer electronics coupled with new technological advancements ... size through 2020   --> ... new technological advancements to drive global touchfree intuitive gesture ...
(Date:1/27/2016)... Ohio , Jan. 27, 2016  Rite Track, ... based in West Chester, Ohio ... award winning service staff, based in Austin, ... capacity and ability to provide modifications, installations and technical ... Dovalina , CEO of PLUS, commented, "PLUS has provided ...
(Date:1/22/2016)... DUBLIN , Jan. 22, 2016 /PRNewswire/ ... announced the addition of the "Global ... report to their offering. --> ... of the "Global Biometrics Market in ... offering. --> Research and ...
Breaking Biology News(10 mins):
(Date:2/5/2016)... , February 5, 2016 ... a biotechnology company focused on developing products for Regenerative ... requested Rare Pediatric Disease Designation (RPDD) from the US ... (RP) with MANF. MANF was previously granted orphan drug ... --> Amarantus BioScience Holdings, Inc. ...
(Date:2/4/2016)... New FDA action date of July 22, ... July 22, 2016   --> - ... - Lifitegrast has the potential to be the only ... signs and symptoms of dry eye disease in adults --> ... approved in the U.S. in the past decade indicated for the treatment of ...
(Date:2/4/2016)... Falls Church, VA (PRWEB) , ... ... ... a first-year cybersecurity conference presented by Bloomsburg University’s Digital Forensics Club, takes ... Bloomsburg, PA. The two-day event features 20+ speakers and activities such as ...
(Date:2/4/2016)... British Columbia and MENLO PARK, Calif. ... (OTCQX: DMPI) ("DelMar" and the "Company"), a biopharmaceutical company ... today announced that it will present at the 18 ... Monday, February 8, 2016 at 10:00 a.m. EST in ... Bacha , DelMar,s president and CEO, will provide an update ...
Breaking Biology Technology: