Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Membranes in tight corners

Photosynthesis takes place in specialized membrane systems, made up of stacked disks linked together by unstacked planar leaflets. An LMU team has now identified a protein that tucks the membrane in at the edge of each stack.

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.

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)

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.

The study was carried out in the context of Collaborative Research Center SFB-TR 1 (Endosymbiosis: From Prokaryotes to Eukaryotic Organelles), and was financed by the DFG.

Luise Dirscherl | EurekAlert!
Further information:

Further reports about: CURT1 LMU Membranes Photosystem crop plant protein complex

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>