6mnn | pdb_00006mnn
6236 TCR bound to I-Ab Padi4
Structural highlights
Function[PADI4_MOUSE] Catalyzes the citrullination/deimination of arginine residues of proteins such as histones, thereby playing a key role in histone code and regulation of stem cell maintenance. Citrullinates histone H1 at 'Arg-54' (to form H1R54ci), histone H3 at 'Arg-2', 'Arg-8', 'Arg-17' and/or 'Arg-26' (to form H3R2ci, H3R8ci, H3R17ci, H3R26ci, respectively) and histone H4 at 'Arg-3' (to form H4R3ci). Acts as a key regulator of stem cell maintenance by mediating citrullination of histone H1: citrullination of 'Arg-54' of histone H1 (H1R54ci) results in H1 displacement from chromatin and global chromatin decondensation, thereby promoting pluripotency and stem cell maintenance. Promotes profound chromatin decondensation during the innate immune response to infection in neutrophils by mediating formation of H1R54ci. Citrullination of histone H3 prevents their methylation by CARM1 and HRMT1L2/PRMT1 and represses transcription. Citrullinates EP300/P300 at 'Arg-2142', which favors its interaction with NCOA2/GRIP1.[1] [2] [3] [4] Publication Abstract from PubMedThe neonatal thymus generates Foxp3(+) regulatory T (tTreg) cells that are critical in controlling immune homeostasis and preventing multiorgan autoimmunity. The role of antigen specificity on neonatal tTreg cell selection is unresolved. Here we identify 17 self-peptides recognized by neonatal tTreg cells, and reveal ligand specificity patterns that include self-antigens presented in an age- and inflammation-dependent manner. Fate-mapping studies of neonatal peptidyl arginine deiminase type IV (Padi4)-specific thymocytes reveal disparate fate choices. Neonatal thymocytes expressing T cell receptors that engage IA(b)-Padi4 with moderate dwell times within a conventional docking orientation are exported as tTreg cells. In contrast, Padi4-specific T cell receptors with short dwell times are expressed on CD4(+) T cells, while long dwell times induce negative selection. Temporally, Padi4-specific thymocytes are subject to a developmental stage-specific change in negative selection, which precludes tTreg cell development. Thus, a temporal switch in negative selection and ligand binding kinetics constrains the neonatal tTreg selection window. A temporal thymic selection switch and ligand binding kinetics constrain neonatal Foxp3(+) Treg cell development.,Stadinski BD, Blevins SJ, Spidale NA, Duke BR, Huseby PG, Stern LJ, Huseby ES Nat Immunol. 2019 Jun 17. pii: 10.1038/s41590-019-0414-1. doi:, 10.1038/s41590-019-0414-1. PMID:31209405[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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