Hibernation factor

A hibernation factor is a protein used by cells to induce a dormant state by slowing or halting the cellular metabolism.

[1] This can occur during periods of stress,[1] randomly in order to allocate "designated survivors" in a population,[1] or when bacteria cease growth (enter stationary phase).

[2] Hibernation factors can do a variety of things, including dismantling cellular machinery and halting gene expression, but the most important hibernation factors bind to the ribosome and halt protein production, which consumes a large fraction of the energy in a cell.

[2] Balon (Spanish "ball", after homologue Pelota)[5] is a hibernation factor protein found in the cold-adapted bacterium Psychrobacter urativorans.

[5] The protein was discovered accidentally by a researcher who unintentionally left a sample of P. urativorans in an ice bucket for too long, cold-shocking it, through subsequent cryo-EM scans of the organism's ribosomes.

[1] Genetic relatives of Balon have been found in 20% of bacterial genomes catalogued in public databases, but are absent from Escherichia coli and Staphylococcus aureus, the most widely used models for cellular dormancy.