Scientists have managed to create artificial cells that produce their own energy via photosynthesis, a process used by plants and a few other organisms that involves harnessing energy from the Sun. The mock cells can then use this energy to grow new parts, an exciting step forward in the field of artificial cells.
All living organisms are made up of vast numbers of teeny tiny cells, and each one of us contains a whopping 37.2 trillion. Our cells produce energy, synthesize proteins, and store genetic information. They are quite literally the basic components of life. Creating artificial cells that act like real-life biological ones is useful to scientists trying to work out both how cells function and how life first came to be. It could also inform medical researchers, such as those working towards the creation of artificial organs for transplants.
Living cells can use energy from their environment to grow new parts. The new research, published in Nature Communications, marks the first time that this feature has been achieved for parts of artificial ones.
A team led by the Tokyo Institute of Technology created the new cells by combining various biological structures. Importantly, the cells contained two proteins called bacteriorhodopsin and ATP synthase. ATP synthase is an enzyme that produces energy in the form of a molecule called adenosine triphosphate (ATP). Meanwhile, bacteriorhodopsin harvests energy from sunlight to boost this process.
The energy made by the proteins was then used by the cells in two processes called transcription and translation, which involve making mRNA from DNA and then protein from mRNA. mRNA, aka messenger RNA, is a subtype of RNA, a molecule that carries the instructions for synthesizing proteins. The artificial cells were able to use the energy they’d harvested to create even more ATP synthase and bacteriorhodopsin, further enhancing their activity.
"I have been trying for a long time to construct a living artificial cell, especially focusing on membranes. In this work, our artificial cells were wrapped in lipid membranes, and small membrane structures were encapsulated inside them,” said research leader Yutetsu Kuruma in a statement. “In this way, the cell membrane is the most important aspect of forming a cell, and I wanted to show the importance of this point in the study of artificial cells and feedback in origins of life studies."
The new research takes scientists a step closer to creating artificial cells that are totally self-sustaining, just like the cells in our bodies. This could help scientists work out how life first arose in the form of simple primordial cells that somehow produced their own energy.
"The most challenging thing in this work was the photosynthesis of the bacteriorhodopsin and the ATP synthase parts, which are membrane proteins. We tried to photosynthesize a full ATP synthase, which has eight kinds of component proteins, but we could not because of the low productivity of the cell-free protein synthesis system,” Kuruma explained. “But, if it was upgraded, we may photosynthesize the whole eight kinds of component proteins."