9e3a
Cryo-EM structure of PRMT5/WDR77 in complex with 6S complex (pICln PBM local refinement)
Structural highlights
FunctionANM5_HUMAN Arginine methyltransferase that can both catalyze the formation of omega-N monomethylarginine (MMA) and symmetrical dimethylarginine (sDMA), with a preference for the formation of MMA. Specifically mediates the symmetrical dimethylation of arginine residues in the small nuclear ribonucleoproteins Sm D1 (SNRPD1) and Sm D3 (SNRPD3); such methylation being required for the assembly and biogenesis of snRNP core particles. Methylates SUPT5H. Mono- and dimethylates arginine residues of myelin basic protein (MBP) in vitro. Plays a role in the assembly of snRNP core particles. May play a role in cytokine-activated transduction pathways. Negatively regulates cyclin E1 promoter activity and cellular proliferation. May regulate the SUPT5H transcriptional elongation properties. May be part of a pathway that is connected to a chloride current, possibly through cytoskeletal rearrangement. Methylates histone H2A and H4 'Arg-3' during germ cell development. Methylates histone H3 'Arg-8', which may repress transcription. Methylates the Piwi proteins (PIWIL1, PIWIL2 and PIWIL4), methylation of Piwi proteins being required for the interaction with Tudor domain-containing proteins and subsequent localization to the meiotic nuage. Methylates RPS10. Attenuates EGF signaling through the MAPK1/MAPK3 pathway acting at 2 levels. First, monomethylates EGFR; this enhances EGFR 'Tyr-1197' phosphorylation and PTPN6 recruitment, eventually leading to reduced SOS1 phosphorylation. Second, methylates RAF1 and probably BRAF, hence destabilizing these 2 signaling proteins and reducing their catalytic activity. Required for induction of E-selectin and VCAM-1, on the endothelial cells surface at sites of inflammation. Methylates HOXA9. Methylates and regulates SRGAP2 which is involved in cell migration and differentiation. Acts as a transcriptional corepressor in CRY1-mediated repression of the core circadian component PER1 by regulating the H4R3 dimethylation at the PER1 promoter.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] Publication Abstract from PubMedProtein arginine methyltransferase (PRMT) 5 is an essential arginine methyltransferase responsible for the majority of cellular symmetric dimethyl-arginine marks. PRMT5 uses substrate adaptors such as pICln, RIOK1, and COPR5 to recruit and methylate a wide range of substrates. Although the substrate adaptors play important roles in substrate recognition, how they direct PRMT5 activity towards specific substrates remains incompletely understood. Using biochemistry and cryogenic electron microscopy, we show that these adaptors compete for the same binding site on PRMT5. We find that substrate adaptor and substrate complexes are bound to PRMT5 through two peptide motifs, enabling these adaptors to act as flexible tethering modules to enhance substrate methylation. Taken together, our results shed structural and mechanistic light on the PRMT5 substrate adaptor function and the biochemical nature of PRMT5 interactors. Substrate adaptors are flexible tethering modules that enhance substrate methylation by the arginine methyltransferase PRMT5.,Jin CY, Hunkeler M, Mulvaney KM, Sellers WR, Fischer ES J Biol Chem. 2025 Jan 8;301(2):108165. doi: 10.1016/j.jbc.2025.108165. PMID:39793893[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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