Light driven proton pump in distant relative

April 10, 2020

Researchers investigated the group of microorganisms classified as Asgard archaea, and found a protein in their membrane which acts as a miniature light-activated pump. The schizorhodopsin protein draws protons into the organisms' body. This research could lead to new biomolecular tools to control the pH in cells or microorganisms, and possibly more.

Asgard archaea are relatively new to science, but they are ancient and important to us in more ways than one. They are single-celled organisms and were originally found at the bottom of the ocean. Asgard archaea are what are known as a prokaryote, they do not have a cell nucleus, yet despite this, they are genetically close to single-celled organisms called eukaryotes which do contain a cell nucleus. They are like a modern analogue of an ancient common ancestor.

The race is on to investigate these small but significant organisms. Associate Professor Keiichi Inoue from the Institute for Solid State Physics at the University of Tokyo, Professor Hideki Kandori from Nagoya Institute of Technology and their team chose to study a feature of Asgard archaea that although not unique to them, is especially interesting in their case, and that is light-sensitive or photoreceptive proteins called rhodopsins. The organisms live at the bottom of oceans and lakes so it's surprising they need any kind of sensitivity to light.

"We explored the molecular function of special rhodopsins in Asgard archaea called schizorhodopsins and found that they acted as light-activated microscopic pumps," explained Inoue. "Schizorhodopsin uses sunlight energy to take up a proton into the cell along a pathway inside the protein. Many prokaryotes such as bacteria and other archaea use rhodopsins to pump protons out, but we find this newly characterized form in Asgard archaea particularly interesting."

As the scale this function occurs on is nanoscopic, sophisticated measurement techniques with high sensitivity and high temporal resolution were required. Inoue, Kandori and their team used a method called laser flash photolysis which uses pulsed laser light to stimulate reactions. Color change in the protein affected by laser light was monitored by sensitive sensors. These detected the presence and nature of the short-lived activation of schizorhodopsin.

"These findings will help us better understand proton and other ion transport mechanisms. In addition, schizorhodopsin could be made into a useful molecular tool for researchers," commented Inoue. "For example in optogenetics, which is a new methodology to control various cellular phenomena with light. Schizorhodopsins could also be used to control the pH inside cells or microorganisms with light, as pH can be altered by changing the proton concentration."
-end-
Journal article

Keiichi Inoue, Satoshi P. Tsunoda, Manish Singh, Sahoko Tomida, Shoko Hososhima, Masae Konno, Ryoko Nakamura, Hiroki Watanabe, Paul-Adrian Bulzu, Horia L. Banciu, Adrian-?tefan Andrei, Takayuki Uchihashi, Rohit Ghai, Oded Béjà, Hideki Kandori. Schizorhodopsins: A family of rhodopsins from Asgard archaea that function as light-driven inward H+ pumps. Science Advances. DOI: 10.1126/sciadv.aaz2441

This work was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI grant numbers JP16H02277, JP17K14536, and JP19K15628.

Inoue Laboratory - https://inoue.issp.u-tokyo.ac.jp/en/index.html

Institute for Solid State Physics - http://www.issp.u-tokyo.ac.jp/index_en.html

Research Contacts

Associate Professor Keiichi Inoue
Institute for Solid State Physics, The University of Tokyo
5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 JAPAN
Tel: +81-4-7136-3230 - Email: inoue@issp.u-tokyo.ac.jp

Professor Hideki Kandori
OptoBiol Technology Research Center, Nagoya Institute of Technology
Gokisocho, Showa-ku, Nagoya, Aichi 466-8555 JAPAN
Tel: +81-52-735-5207 - Email: kandori@nitech.ac.jp

Press Contacts

Ms. Madoka Mochida
Institute for Solid State Physics, The University of Tokyo
5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 JAPAN
Email: press@issp.u-tokyo.ac.jp

Mr. Rohan Mehra
Division for Strategic Public Relations, The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, JAPAN
Tel: +81-3-5841-0876 - Email: press-releases.adm@gs.mail.u-tokyo.ac.jp

About the University of Tokyo

The University of Tokyo is Japan's leading university and one of the world's top research universities. The vast research output of some 6,000 researchers is published in the world's top journals across the arts and sciences. Our vibrant student body of around 15,000 undergraduate and 15,000 graduate students includes over 4,000 international students. Find out more at http://www.u-tokyo.ac.jp/en/ or follow us on Twitter at @UTokyo_News_en.

University of Tokyo

Related Microorganisms Articles from Brightsurf:

A more resistant material against microorganisms is created to restore cultural heritage
The study was performed by a research team at the University Research Institute into Fine Chemistry and Nanochemistry at the University of Cordoba and Seville's Institute of Natural Resources and Agrobiology of the Spanish National Research Council

NYUAD study finds gene targets to combat microorganisms binding to underwater surfaces
A group of synthetic biologists at NYU Abu Dhabi (NYUAD) have identified new genetic targets that could lead to safe, biologically-based approaches to combat marine biofouling - the process of sea-based microorganisms, plants, or algae binding to underwater surfaces.

Less flocking behavior among microorganisms reduces the risk of being eaten
When algae and bacteria with different swimming gaits gather in large groups, their flocking behaviour diminishes, something that may reduce the risk of falling victim to aquatic predators.

Are vultures spreaders of microbes that put human health at risk?
A new analysis published in IBIS examines whether bacteria, viruses, and other microorganisms that are present in wild vultures cause disease in the birds, and whether vultures play a role in spreading or preventing infectious diseases to humans and other animal species.

Timing key in understanding plant microbiomes
Oregon State University researchers have made a key advance in understanding how timing impacts the way microorganisms colonize plants, a step that could provide farmers an important tool to boost agricultural production.

Advances in the production of minor ginsenosides using microorganisms and their enzymes
Advances in the Production of Minor Ginsenosides Using Microorganisms and Their Enzymes - BIO Integration https://bio-integration.org/wp-content/uploads/2020/05/bioi20200007.pdf Announcing a new article publication for BIO Integration journal.

Study shows how microorganisms survive in harsh environments
In northern Chile's Atacama Desert, one of the driest places on Earth, microorganisms are able to eke out an existence by extracting water from the rocks they colonize.

Microorganisms in parched regions extract needed water from colonized rocks
Cyanobacteria living in rocks in Chile's Atacama Desert extract water from the minerals they colonize and, in doing so, change the phase of the material from gypsum to anhydrite.

Verticillium wilt fungus killing millions of trees is actually an army of microorganisms
A research project studied the microbiome of olive tree roots and concluded that Verticillium wilt is fueled by a community of microorganisms that team up to attack plants, thus reassessing the way this problem is dealt with

New drug formulation could treat Candida infections
With antimicrobial resistance (AMR) increasing around the world, new research led by the University of Bristol has shown a new drug formulation could possibly be used in antifungal treatments against Candida infections.

Read More: Microorganisms News and Microorganisms Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.