8idt

Structural highlights

Function

IF6_HUMAN Binds to the 60S ribosomal subunit and prevents its association with the 40S ribosomal subunit to form the 80S initiation complex in the cytoplasm (PubMed:10085284, PubMed:14654845, PubMed:21536732, PubMed:32669547). Behaves as a stimulatory translation initiation factor downstream insulin/growth factors. Is also involved in ribosome biogenesis. Associates with pre-60S subunits in the nucleus and is involved in its nuclear export. Cytoplasmic release of TIF6 from 60S subunits and nuclear relocalization is promoted by a RACK1 (RACK1)-dependent protein kinase C activity (PubMed:10085284, PubMed:14654845, PubMed:21536732). In tissues responsive to insulin, controls fatty acid synthesis and glycolysis by exerting translational control of adipogenic transcription factors such as CEBPB, CEBPD and ATF4 that have G/C rich or uORF in their 5'UTR. Required for ROS-dependent megakaryocyte maturation and platelets formation, controls the expression of mitochondrial respiratory chain genes involved in reactive oxygen species (ROS) synthesis (By similarity). Involved in miRNA-mediated gene silencing by the RNA-induced silencing complex (RISC). Required for both miRNA-mediated translational repression and miRNA-mediated cleavage of complementary mRNAs by RISC (PubMed:17507929). Modulates cell cycle progression and global translation of pre-B cells, its activation seems to be rate-limiting in tumorigenesis and tumor growth (By similarity).[HAMAP-Rule:MF_03132]^{[1] [2] [3] [4] [5]}

See Also

• Ribosome 3D structures
• Ribosome biogenesis protein 3D structures

References

1. ↑ Sanvito F, Piatti S, Villa A, Bossi M, Lucchini G, Marchisio PC, Biffo S. The beta4 integrin interactor p27(BBP/eIF6) is an essential nuclear matrix protein involved in 60S ribosomal subunit assembly. J Cell Biol. 1999 Mar 8;144(5):823-37. PMID:10085284
2. ↑ Ceci M, Gaviraghi C, Gorrini C, Sala LA, Offenhäuser N, Marchisio PC, Biffo S. Release of eIF6 (p27BBP) from the 60S subunit allows 80S ribosome assembly. Nature. 2003 Dec 4;426(6966):579-84. PMID:14654845 doi:10.1038/nature02160
3. ↑ Chendrimada TP, Finn KJ, Ji X, Baillat D, Gregory RI, Liebhaber SA, Pasquinelli AE, Shiekhattar R. MicroRNA silencing through RISC recruitment of eIF6. Nature. 2007 Jun 14;447(7146):823-8. Epub 2007 May 16. PMID:17507929 doi:http://dx.doi.org/10.1038/nature05841
4. ↑ Finch AJ, Hilcenko C, Basse N, Drynan LF, Goyenechea B, Menne TF, Gonzalez Fernandez A, Simpson P, D'Santos CS, Arends MJ, Donadieu J, Bellanne-Chantelot C, Costanzo M, Boone C, McKenzie AN, Freund SM, Warren AJ. Uncoupling of GTP hydrolysis from eIF6 release on the ribosome causes Shwachman-Diamond syndrome. Genes Dev. 2011 May 1;25(9):917-29. PMID:21536732 doi:10.1101/gad.623011
5. ↑ Liang X, Zuo MQ, Zhang Y, Li N, Ma C, Dong MQ, Gao N. Structural snapshots of human pre-60S ribosomal particles before and after nuclear export. Nat Commun. 2020 Jul 15;11(1):3542. PMID:32669547 doi:10.1038/s41467-020-17237-x