Varuni Ankolekar, Quartesian
A research led by Helmholtz Zentrum München has revealed that a membrane-remodeling protein known as Vesicle-inducing protein in plastids 1 (VIPP1) plays a significant role in biogenesis and nurturing of thylakoid membranes, which helps in photosynthesis in plants. It also bolsters plants to fight against environmental stress.
Humans are found to release stress by Exercising, Connecting with Supportive People, carving out Hobby Time, Practicing Meditation or Yoga, Sleeping, eating ice cream or favorite food. Research have found that animals deal by eating comfort food and they do not mull things over unlike humans. How do plants deal with environmental stress?
Photosynthesis:
Plants, algae, and cyanobacteria perform photosynthesis, to produce food from sunlight, carbon dioxide and water in the atmosphere, that is their key source of energy. Water is split to generate the Earth’s oxygen. The electrons and H+ liberated from this reaction produces NADPH and ATP which is in turn used to eliminate CO2 from the atmosphere and convert it into the glucose. It releases oxygen as a byproduct without which oxygen-requiring life would not stay alive and plants would perish. Making use of carbon dioxide (CO2) from the atmosphere during this process has reduced the accumulation of the greenhouse gas. However, they undergo environmental stress due to climate change which hinders their growth and might jeopardize the food resource to other organisms in future if this last.
Main site of photosynthesis:
Chloroplast is the organelle in plants which is the site of photosynthesis and consists of Granum, Chloroplast envelope (Outer membrane, Intermembrane space, Inner membrane), Granal thylakoid, Thylakoid (Thylakoid space, Thylakoid membrane), Stromal thylakoid, Stroma, Nucleoid (DNA ring), Ribosome, Plastoglobulus, Starch granule.
The main site of photosynthesis inside chloroplasts is Thylakoid membrane, which contain VIPP1 proteins that collect sunlight. Although it is recognized long time ago that these proteins are responsible for building thylakoid membranes in almost all photosynthetic organisms, how VIPP1 performs this essential function was not evident. Ben Engel and team studied the structure and mechanism of VIPP1 to reveal this mystery.
Structure and mechanism of VIPP1:
Analysis of structure and mechanism of VIPP1 was done using cryo-electron microscope which facilitates to produce first high-resolution image of VIPP1. VIPP1 remodels and convenes itself into an interlocked coating that shapes the thylakoid membranes. VIPP1 monomers curve and interlace to take shape of basket like structure of Thylakoid. Three VIPP1 monomers organize a non-canonical nucleotide binding pocket on one end of the ring that would be necessary to form VIPP1 oligomerization. In the space of these rings, the amphipathic helices from every monomer align to develop large hydrophobic columns, allowing VIPP1 to bind and curve membranes. Introduction of mutations in these hydrophobic surfaces cause extreme thylakoid swelling under high light. It was evident that interaction of VIPP1 with thylakoid membranes plays a substantial role in maintenance of these membranes under high-light stress when specific mutations to VIPP1 were made, once the structural information was identified.
Ben Engel and team uncovered how VIPP1 proteins combine, hydrolyzes nucleotides, and binds lipids with the help of Cryo-EM. Integrity of thylakoid under high-light stress is possible due to Lipid binding mediated by VIPP1’s H1 helix. The contact between thylakoids and the chloroplast envelope is aided by VIPP1 coats.
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Reference:
- Benjamin D. Engel et al, Structural basis for VIPP1 oligomerization and maintenance of thylakoid membrane integrity, Cell (2021). DOI: 10.1016/j.cell.2021.05.011
About author:
Varuni Ankolekar is currently a Clinical Data Management professional with a demonstrated history of working in the pharmaceuticals industry. She is skilled in Clinical Data Management and Healthcare. She is a strong research professional with a Bachelor of Engineering (B.E.) focused in Biotechnology, from The Oxford College of Engineering . Some of her previous publications at BioXone are:
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