Researchers have uncovered a mechanism driving the emergence of multicellular life, linking it to alterations in protein folding. In a recent investigation led by teams from the University of Helsinki and the Georgia Institute of Technology, scientists utilized experimental evolution techniques. Through the ongoing Multicellularity Long Term Evolution Experiment (MuLTEE), laboratory yeast underwent evolutionary processes, leading to the development of new multicellular functions. This study emphasizes the significance of protein regulation in understanding evolutionary processes.
Associate Professor Juha Saarikangas from the University of Helsinki explains, “By showcasing the impact of protein-level modifications on evolutionary changes, this research underscores the necessity to delve beyond genetic coding alone for a comprehensive comprehension of adaptive behaviors. Understanding such phenomena requires a thorough exploration of the entire genetic information flow, including its influence on protein states which ultimately dictate cellular behavior.”
Over 3,000 generations, the yeast, termed ‘snowflake yeast,’ evolved robust bodies, transitioning from fragility to strength comparable to wood. The researchers identified a non-genetic mechanism affecting this multicellular trait at the protein folding level. They discovered that the expression of the chaperone protein Hsp90, crucial for ensuring proper protein folding, decreased gradually as the yeast developed larger, tougher bodies. Hsp90 played a pivotal role in destabilizing a key molecule regulating the cell cycle, resulting in elongated cells. This elongated shape facilitated cell wrapping, leading to the formation of larger, mechanically resilient multicellular structures.
Lead author Kristopher Montrose from the University of Helsinki elaborates, “Hsp90, known for its role in protein stabilization and folding, was revealed to have significant influence beyond individual cells, profoundly shaping the nature of multicellular organisms through subtle modifications in its function.”
This study underscores the potency of non-genetic mechanisms in driving rapid evolutionary changes. Professor Will Ratcliff from the Georgia Institute of Technology remarks, “While genetic alterations often take the spotlight, the substantial impact of changes in chaperone protein behavior highlights the ingenuity and unpredictability of evolution in addressing novel challenges, such as the development of robust body structures.”
