From Genomes to Biological Systems: Understanding molecular machinery
Our lives are surrounded by man-made structures, from the simple self-assembled furniture in our homes to the massive bridges and motorways that connect cities and countries. Regardless of how complex a piece of furniture or a bridge may be, there needs to be a blueprint in order to make the pieces fit together and function as a whole.
But what about the structures that aren’t man-made, like the proteins and cells in our body? How are these complex biological structures put together, and can we learn how to use these biological blueprints to build cells of our own? Dr. Luning Liu, a Royal Society Fellow at IIB, is working with his interdisciplinary group to better understand the blueprints that describe how living organisms are put together.
Luning joined the University of Liverpool in December 2012 as a Tenure Track Fellow, subsequently moving to a Royal Society Fellowship. The Liu lab is focused on learning how nano-scaled biological machinery are assembled, and one of their interests is in how the parts of algae cells that control photosynthesis are put together. “During photosynthesis, the specialised cell membrane converts solar light into the chemical energy that supports the life on Earth, and we’re using cyanobacteria to understand how these cells build devices that can capture and convert light energy. We can then use that information to learn how we can build our own devices that we can use to enhance the movement of energy within a cell” said Luning.
Cyanobacteria are known as ‘blue-green algae’ and are a type of bacteria that get their energy from the sun. During photosynthesis, the energy from light hits the external membranes of the cell, which break down water into oxygen molecules and generate protons (in the form of hydrogen atoms) and free electrons. The protons are then used to produce energy molecules that the cell can use to generate sugars, amino acids, and starches through the Calvin-Benson cycle. These bacteria have also developed specialised carbon fixation mechanisms, using biological structures known as carboxysomes. Carboxysomes are used to help bacteria get enough carbon so they can complete photosynthesis.
Luning and his group are working on how the photosynthetic machinery in cyanobacteria is organised and how the cells optimise these biochemical reactions to efficiently harvest solar energy and accumulate carbon. In a recent publication from the Liu lab, his group were able to add fluorescent tags to the carboxysomes. These tagged proteins allowed them to track the location and amount of the carbon-trapping carboxysomes while the bacteria were growing. The Liu lab were able to see first-hand how carboxysome movement could be linked to the energy state of the bacterial cell and how they allow the cyanobacteria to optimise how carbon is uptaken depending on the amount of light present.
One of the big picture goals of Luning’s research isn’t just to better understand photosynthesis and carbon fixation, but to work towards design systems that are more efficient, especially in terms of food and biofuel security. “Our goal is to improve the process of photosynthesis so we can improve yields of a wide range of food crops” Luning said.
One challenge faced by the Liu lab is the role of their work in the realm of genetically modified organisms. While his group works primarily on fundamental research, he has encouraged members of his group to be ready for questions on the topic when doing public engagement work and when applying for grants about their research. “Our research has potentially a lot of promise to make a difference but we have to be solid on understanding technology and the mechanism before we can apply them in the real world” added Luning.
Luning and his group work with plant scientists, biophysicists, chemists, synthetic biologists, and microbiologists: a truly interdisciplinary approach towards a better understanding of these complex biological structures. Luning commented: “Nowadays all work in science is multidisciplinary, and you can’t use one technique to solve everything. The advantage in our group is that there are advanced technologies that we can use to bring our ideas to life. We can ask questions about how natural structures are built in the cells and then work with plant scientists who are looking for a fundamental understanding of the system to see what approaches and techniques they use.”
Luning regularly sends students to technical workshops so they can gain more knowledge and training in the latest technologies and techniques. However he also makes sure that he and his group stick to the basic principles of the scientific method. “I focus on the question more than just the technique by itself. You can use lots of different techniques and technologies to do science, but having a clear question is the most important starting point. The biggest challenge is that there is no one who can tell you what will work, so you really have to explore lots of ideas and try a lot of things before you get something that works” said Luning.
Luning received his undergraduate degree in Biochemistry before earning a joint PhD in microbiology from Shandong University (China) and Leiden University (Netherlands). After spending 2 years carrying out research on biological membranes at the Institute Curie in Paris, he started working on cyanobacteria as a researcher at Queen Mary University of London before joining IIB in 2012. Luning describes himself as driven by curiosity: “Every day is exciting; there are new technologies and papers to keep up with, working with my students on their projects, and reaching out to new collaborators. I enjoy discussing and exploring new ideas by working with colleagues in such an open-minded work environment at IIB.”
The Liu lab currently consists of seven PhD students, one post-doc and one technician. Luning works to recruit a multidisciplinary team in his lab, including researchers specialising in molecular biology, biochemistry, biophysics, and plant science. This diverse approach allows group members to learn from one another and enables them to approach problems with different types of perspectives. “Sometimes the biology students have a hard time with the physics, so having a diverse team with diverse sets of skills and knowledge is crucial to making these complex experiments work.” Luning commented.
Luning can regularly be found working in the lab alongside his students and post-doc while encouraging his students to enjoy this time in their research careers as much as possible. Luning replied when asked what his students thought about having their boss pipetting alongside them: “Being a PhD student is the most exciting time in a scientist’s career, because it’s a time when you get to focus on the research and not have to deal with the stressors of applying for grants and funding. I try to help them enjoy this time as much as possible and to help them out.”
Luning is also focused on achieving his own life-work balance, spending the hours from 9am to 5pm in the lab and office before heading home to spend time with his two young children. He then finishes off the evening hours with grant applications, papers, and emails. “The job can be very stressful, especially since this is a very new area, and I try to work hard to stay on top of things. It’s also tough since my kids need my time too, so I don’t go to as many big conferences now so I can spend more time with my family. It’s important to make time for family and do things apart from work”.