Jonikas Lab

Research

180707_Pyrenoid.jpg
 

We seek to understand and engineer the algal CO2 turbocharger.

The pyrenoid is a mysterious algal structure that mediates approximately one-third of global CO2 fixation. Nearly all eukaryotic algae in the oceans use a pyrenoid to assimilate CO2. Despite its importance to the global carbon cycle, until very recently, the pyrenoid has remained almost completely uncharacterized at a molecular level.

We aim to transform our understanding of pyrenoid protein composition, structure and function. We recently discovered ~90 protein components of the pyrenoid, and determined their sub-pyrenoid localization and physical interactions. Among them, we identified a key protein that we think holds the carbon-fixing enzyme Rubisco together in the pyrenoid. We also discovered that the pyrenoid behaves as a phase-separated, liquid-like organelle, not as a crystalline solid as it has long been thought to be.

If we understood how a pyrenoid works, we could engineer it into crop plants to increase yields by enhancing CO2 uptake. With our collaborators, we are starting to engineer the components we are discovering into model higher plants, with the dream of ultimately increasing global yields of wheat and rice.