ATP Synthase including Proteomics

Lead Research Organisation: University of Cambridge

Abstract

Energy from the sun is entrapped by photosynthesis and stored in high energy compounds that we consume in food. The energy is released by controlled burning in the mitochondria in the cells of our bodies, and stored in the high energy compound adenosine triphosphate, ATP, the fuel of biology. ATP is made in the mitochondria inside our cells. They are “power stations” full of millions of molecular turbines, the ATP synthases that rotate like man-made turbines and churn out ATP in massive quantities. We understand most of how these molecular turbines work, but not how rotation is generated. This project will provide the missing information. Bacteria have turbines that differ significantly from the human ones, and they are controlled by different mechanisms. We want to understand these differences in structure, function and regulation so as to devise drugs to kill pathogenic bacteria by stopping their turbines without influencing the human ones.

Technical Summary

The F-ATP synthases in eubacteria and mitochondria are rotary machines with many common features. We will build on past achievements to extend fundamental knowledge about them and provide a basis for putting that knowledge to practical use. The mechanism of their catalytic domains is well understood, but how rotation is generated from the transmembrane proton-motive force is less clear. We will provide a molecular explanation of the generation of rotation. We intend to exploit mechanistic differences between human and bacterial enzymes to develop new drugs. One difference concerns their mechanisms of regulation. The mitochondrial enzyme is regulated by the inhibitor protein, IF1; in vitro, it inhibits ATP hydrolysis and not ATP synthesis, but its in vivo role is unclear, except that it inhibits the hydrolase activity of assembly intermediates. It may also inhibit in vivo ATP synthesis by a mechanism that we will investigate possible involving other unidentified proteins. Different regulatory mechanisms operate in eubacteria; for example in Mycobacteria, the enzyme can only make ATP and not hydrolyze it, but we do not yet know how hydrolysis is prevented. Eubacterial and mitochondrial enzymes differ also in their subunit compositions. They have a common core set to allow them to make ATP, but the mammalian mitochondrial enzymes have a "supernumerary" set of seven membrane proteins, each with a single predicted transmembrane a-helix. In mitochondria, these supernumerary subunits form an interface between monomeric complexes in the dimeric arrangements found in the inner membranes of the organelle. We are determining the structure of the dimeric complex to gain detailed information about how the membrane domain of the enzyme functions. As part of a wider collaboration we will study how the human ATP synthase is assembled.

Publications

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Carroll J (2019) Persistence of the permeability transition pore in human mitochondria devoid of an assembled ATP synthase. in Proceedings of the National Academy of Sciences of the United States of America

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Carroll J (2021) TMEM70 and TMEM242 help to assemble the rotor ring of human ATP synthase and interact with assembly factors for complex I. in Proceedings of the National Academy of Sciences of the United States of America

 
Description Cambridge Science Festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Showcasing the MBU's science to the general pubiic - "Discovering the mechanism of energy production in mitochondria". Games and activities: Destroying mutant mitochondrial DNA; Electron Transport Pinball; Fluorescent Light Microscopy.
Impact: Discussions about career pathways, enquiries about internships and potential collaborations.
Year(s) Of Engagement Activity 2019
 
Description IGEM - Aachen 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Discussion about the iGEM Project; presentation about the ATP synthase; and the story about John Walker's journey towards the Nobel Prize in Chemistry.

Feedback from the organsers:
Have you ever asked yourself, how do people get a Nobel Prize? What kind of mindset do they have? What is their secret of success?
We got our answers. And those answers came from the Nobel Prize Laureate himself, Sir John E. Walker.We were able to talk about our project, attend his presentation about the ATP synthase and just listen to his journey until one of the biggest achievements of humanity, namely the Nobel Prize in Chemistry.
We are still humbled about such an experience and want to energize everyone to keep dreaming! Dream and go for it!
Year(s) Of Engagement Activity 2020
URL http://www.igem.rwth-aachen.de/?fbclid=IwAR0NHBox610wy7sGJRMIu2Xxqg4K-9qs4vhfEJUGSN-zPV56sr6pwYV0tRc
 
Description Images for the MBU website 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Supply of images for the MBU's website.
Year(s) Of Engagement Activity 2019,2022
 
Description Longsands Academy 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Visit to the MRC MBU by 21 students in Year 13 (16-18 years of age). "Biology Masterclass", followed by tour of unit (fly lab) and an explanation of ATP synthase and the Lego model. "Meet the scientists" session. The students went on to visit CIMR during the afternoon. Collaboratively organised event.
Year(s) Of Engagement Activity 2019
 
Description Online promotion of the MBU 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Regular contributions to online activities in the promotion of the MBU's research, via the Unit's website, facebook, Twitter and other social media accounts.
Impact: increased awareness.
Year(s) Of Engagement Activity 2019,2020,2021,2022
 
Description Visit by Secondary School Students from Jersey 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Visit to the MRC MBU by 10 students ranging between 14-17 years of age. "Biology Masterclass", followed by tour of unit (fly lab) and an explanation of ATP synthase (with the Lego model) from John Walker. Finished with "meet the scientists" session and games.
The students were accompanied by four tutors.
Year(s) Of Engagement Activity 2020
 
Description XIII Oon Lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact XIII Oon Lecture, delivered by Professors Patrick Chinnery and John Walker, at Downing College, University of Cambridge. Lecture title: Mitochondria: from molecules to medicine. Streamed online via YouTube.
Year(s) Of Engagement Activity 2022
URL https://www.youtube.com/watch?v=1i60Cyay04I