New model of the quality control of photosystem II

Jun 25, 2014
Figure caption: Degradation of the D1 protein by proteases.

Thylakoid membranes are piled up to form the grana well known as the site where the Photosystem II (PSII) complexes which play a role in the primary photochemical reaction exist. However, the structures and dynamics of thylakoid membranes are still unclear. In higher plants, the D1 protein binding to the reaction center of PSII is easily damaged by strong light, which leads the decrease of photosynthetic efficiency. The damaged D1 protein is removed immediately by FtsH proteases located near the PSII, and the newly synthesized D1 protein is inserted in the D1-depleted PSII complex. This maintenance system keeps photosynthetic activity under light stress.

Now, it has been revealed that the molecular process of quality control of PSII described above has a close relationship with the structural changes of thylakoid membranes. M. Y.-Nishimura and Y. Yamamoto at Okayama University proposed the new model of the quality control of PSII focused on the structure of thylakoid membranes.

Figure caption: Unstacking of the thylakoid membranes.

Under normal conditions, FtsH proteases do not migrate easily on the thylakoid membranes because of the narrow space of the partition gap of grana. When thylakoid membranes are subjected to excessive light, the stacks of thylakoid membranes were found to be unstacked. This structural change of the thylakoid membranes is helpful for the migration of the FtsH proteases to access the damaged D1 protein. In the future, more investigations about the structure of thylakoid membranes will be needed for the complete understanding of the dynamics in the of PSII.

Explore further: New insight into photosynthesis

More information: Miho Yoshioka-Nishimura, Yasusi Yamamoto, Quality control of Photosystem II: "The molecular basis for the action of FtsH protease and the dynamics of the thylakoid membranes," Photochemistry and Photobiology B: Biology, Available online 4 March 2014, ISSN 1011-1344, dx.doi.org/10.1016/j.jphotobiol.2014.02.012.

add to favorites email to friend print save as pdf

Related Stories

Membranes in tight corners

Jul 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 ...

New insight into photosynthesis

May 27, 2014

The way that algae and plants respond to light has been reinterpreted based on results from experiments studying real-time structural changes in green algae. Under particular lighting conditions during photosynthesis, ...

Recommended for you

Oat breakfast cereals may contain a common mold-related toxin

Feb 25, 2015

Oats are often touted for boosting heart health, but scientists warn that the grain and its products might need closer monitoring for potential mold contamination. They report in ACS' Journal of Agricultural and Food Chemistry that s ...

NETL invents improved oxygen carriers

Feb 24, 2015

One of the keys to the successful deployment of chemical looping technologies is the development of affordable, high performance oxygen carriers. One potential solution is the naturally-occurring iron oxide, ...

Research could make blue jeans green

Feb 23, 2015

Who doesn't like blue jeans? They're practically wrinkle-proof. The indigo dye that provides their distinctive color holds up to detergents, but ages into that soft, worn look. No wonder the average American ...

Novel electrode boosts green hydrogen research

Feb 20, 2015

Scientists from the National Physical Laboratory (NPL) have developed a novel reference electrode, and are working with hydrogen energy system manufacturer ITM Power to aid the development of hydrogen production ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.