9pbe
In situ human 80S ribosome (composite map)
Structural highlights
FunctionSERB1_HUMAN 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).[UniProtKB:Q9CY58][1] [2] [3] Publication Abstract from PubMedComprehensive in situ structures of macromolecules can transform our understanding of biology and advance human health. Here, we map protein synthesis inside human cells in detail by combining automated cryo-focused ion beam (FIB) milling and in situ single-particle cryo electron microscopy (cryo-EM). With this in situ cryo-EM approach, we resolved a 2.2 A consensus structure of the human 80S ribosome and unveiled 23 functional states, nearly all better than 3 A resolution. Compared to in vitro studies, we observed variations in ribosome structures, distinct environments of ion and polyamine binding, and associated proteins such as EDF1 and NACbeta that are typically not enriched with purified ribosomes. We also detected additional peptide-related density features on the ribosome and visualized ribosome-ribosome interactions in helical polysomes. Finally, high-resolution structures from cells treated with homoharringtonine and cycloheximide revealed a distinct translational landscape and a spermidine that interacts with cycloheximide at the E site, one of the numerous polyamines that also bind native ribosomes. These results underscore the value of high-resolution in situ studies in the native environment. Visualizing the translation landscape in human cells at high resolution.,Zheng W, Zhang Y, Wang J, Wang S, Chai P, Bailey EJ, Zhu C, Guo W, Devarkar SC, Wu S, Lin J, Zhang K, Liu J, Lomakin IB, Xiong Y Nat Commun. 2025 Nov 28;16(1):10757. doi: 10.1038/s41467-025-65795-9. PMID:41315256[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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