Ribosome-binding protein that promotes ribosome hibernation, a process during which ribosomes are stabilized in an inactive state and preserved from proteasomal degradation (PubMed:36691768). Acts via its association with EEF2/eEF2 factor, sequestering EEF2/eEF2 at the A-site of the ribosome and promoting ribosome stabilization and storage in an inactive state (By similarity). May also play a role in the regulation of mRNA stability: binds to the 3′-most 134 nt of the SERPINE1/PAI1 mRNA, a region which confers cyclic nucleotide regulation of message decay (PubMed:11001948). Seems to play a role in PML-nuclear bodies formation (PubMed:28695742).