Navigation Links
Photosynthesis: Membranes in tight corners
Date:7/10/2013

Photosynthesis takes place in specialized membrane systems, made up of stacked disks linked together by unstacked planar leaflets. A team of Ludwig-Maximilians-Universitaet (LMU) in Munich has now identified a protein that tucks the membrane in at the edge of each stack.

Scanning electron microscopy (SEM) micrograph of a chloroplast in maize (Zea mays) showing thylakoids (green) and assimilation starch granules (grey). (Prepared by freeze fracturing; micrograph is pseudo-colored.) (Source: G. Wanner LMU)

By making use of sunlight to generate molecular oxygen and other energy-rich chemical compounds that other organisms can utilize as nutrients, photosynthesis provides the basis for almost all life on Earth. Radiant energy from the Sun is captured by pigment-protein complexes embedded in specialized membrane systems called thylakoids. The thylakoids of green plants reside within organelles called chloroplasts, membrane-bounded compartments in the cell cytoplasm that serve as self-contained reaction vessels.

Thylakoids are made of stacks of 5 to 20 flat membrane sacs called grana, and extended planar membrane sheets that serve to interconnect them, so that all thylakoids in a chloroplast form a continuous network. To form the stacks of appressed sacs, the membrane must be bent into a tight fold at their edges. This implies that the thylakoid membranes forming the grana stacks must somehow be induced to curve at regular intervals. "The origin of the stacked organization of the thylakoids and the local alterations in membrane curvature has been a complete mystery up to now," says LMU biologist Professor Dario Leister.

Leaning into the curve with CURT1

Leister and his group have now identified a new family of proteins, whose members spontaneously cause membranes to bend. The researchers call them CURT1 proteins (for CURvature of Thylakoids). "Without CURT1 proteins, there are no stacks," Leister reports. Using the model plant Arabidopsis, he and his colleagues have been able to show that the concentration of CURT is directly correlated with the number of thylakoid stacks in chloroplasts. CURT1 itself is primarily localized at the edges of the grana, exactly where the membrane is maximally curved. In addition, the researchers have shown in the test-tube that isolated CURT1 molecules spontaneously assemble into larger complexes that can alter the curvature of membranes. "It is therefore likely that the aggregation of several CURT1 molecules plays an important role in the formation of thylakoid stacks in the chloroplasts," Leister concludes.

In the longer term, the new findings could contribute to the optimization of photosynthesis. The grana stacks in the thylakoids are enriched for the antennal proteins that gather and channel light energy and the reaction centers known as Photosystem II. They are therefore, in many respects, more efficient energy converters than the single-layered membrane sheets that connect them together, which harbor Photosystem I. Understanding how CURT1 functions might therefore allow one to increase the degree of stacking and enhance the efficiency of photosynthesis and perhaps increase yields from crop plants. In cooperation with the Edmund Mach Foundation (Trento, Italy) and the University of Trento, the authors of the new study have applied for patent protection for the use of CURT1 in this setting.


'/>"/>

Contact: Luise Dirscherl
dirscherl@lmu.de
49-892-180-2706
Ludwig-Maximilians-Universitt Mnchen
Source:Eurekalert

Related biology news :

1. Photosynthesis: The last link in the chain
2. Modifications of a nanoparticle can change chemical interactions with cell membranes
3. Patel recognized with NSF Career Award for computer-modeling research on cell membranes
4. Laser liposuction melts fat, results in tighter skin
5. Researchers find critical regulator to tightly control deadly pulmonary fibrosis
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/5/2017)... KEY FINDINGS The global market ... CAGR of 25.76% during the forecast period of 2017-2025. ... for the growth of the stem cell market. ... MARKET INSIGHTS The global stem cell market is segmented ... The stem cell market of the product is segmented ...
(Date:3/30/2017)... ANGELES , March 30, 2017  On April ... Hack the Genome hackathon at Microsoft,s ... exciting two-day competition will focus on developing health and ... Hack the Genome is the ... been tremendous. The world,s largest companies in the genomics, ...
(Date:3/29/2017)... 29, 2017  higi, the health IT company that ... North America , today announced a Series B ... of EveryMove. The new investment and acquisition accelerates higi,s ... to transform population health activities through the collection and ... higi collects and secures data today on behalf ...
Breaking Biology News(10 mins):
(Date:8/15/2017)... ... 15, 2017 , ... Nanomedical Diagnostics , a cutting-edge ... the launch of the new NHS Agile biosensor chip . The new ... a wide range of molecules, including small and large molecules, peptides, proteins, and ...
(Date:8/15/2017)... ... August 15, 2017 , ... The Conference Forum ... Immuno-Oncology 360° (IO360°) programming through a series of upcoming panels and events. The partnership ... 2018, at The Roosevelt Hotel in New York City. , “With our experience in ...
(Date:8/14/2017)... ... August 14, 2017 , ... Opal ... using USB or PCI Express, announced the release of SYZYGY™, a new open ... satisfy the need for a compact, low cost, low pin-count, high-performance connectivity solution ...
(Date:8/11/2017)... ... August 11, 2017 , ... Algenist continues to disrupt the ... collagen like never before. , Collagen is the key structural element skin needs ... Liquid Collagen™, which include: , First to market with ...
Breaking Biology Technology: