Researchers have discovered an intriguing survival mechanism in yeast cells under stress, where ribosomes – the cell’s protein factories – hibernate on mitochondria to conserve energy. This adaptation could hold important insights for understanding cancer cell behavior and improving treatment. Ribosomes and mitochondria are essential components of eukaryotic cells, including those in humans.
Yeast Cells’ Remarkable Adaptation to Starvation
Yeast, a common organism used in brewing and baking, has long been a valuable model for studying fundamental cellular processes. Researchers from the European Molecular Biology Laboratory (EMBL) Heidelberg’s Mattei Team and the University of Virginia School of Medicine have uncovered a fascinating adaptation that yeast cells utilize during times of stress, such as nutrient deprivation.
They observed that when yeast cells are starved, their mitochondria – the powerhouses of the cell – become coated with a swarm of massive molecular complexes called ribosomes. Ribosomes are the cell’s protein-producing machinery, responsible for translating genetic information into functional proteins. However, in these starving yeast cells, the ribosomes attached to the mitochondria are not actively producing proteins. Instead, they are in a state of hibernation, conserving energy until better days arrive.
Ribosomes’ Unusual Attachment to Mitochondria
What makes this observation even more intriguing is the way the ribosomes are attaching to the mitochondrial outer membrane. Traditionally, ribosomes were known to interact with membranes through their large subunit, but in these starving yeast cells, the researchers observed that the ribosomes were attaching in an upside-down manner, using their small subunit instead.
“So far, ribosomes were known to interact with membranes only via their large subunit. But in starved cells, we saw that they do this upside-down, via the small subunit,” said Simone Mattei, the team leader. The team is now investigating the specific mechanisms behind this unusual attachment, which could hold valuable insights into cellular adaptation strategies.
Lessons from Yeast for Understanding Cancer Cell Behavior
The struggles of the starved yeast cells bear some similarities to the challenges faced by cancer cells. When a tumor becomes aggressive, its cells grow rapidly, outpacing the available supply of nutrients and oxygen. This means that most cancer cells are constantly in a state of starvation, a “hell they create for themselves,” as described by Ahmad Jomaa, an assistant professor and group leader at the University of Virginia’s School of Medicine.
Understanding the principles behind how yeast cells adapt to starvation and enter a dormant state to survive could provide valuable insights for cancer research. “That’s why we need to understand the basics of adaptation to starvation and how these cells become dormant to stay alive and avoid death,” said Jomaa. By studying the yeast model first, researchers can then apply those learnings to investigate how cultured cancer cells overcome starvation, which is a critical step in developing more effective cancer treatments.
