7kp0

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CD1a-42:1 SM binary complex

Structural highlights

7kp0 is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.4Å
Ligands:EDO, WUA
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CD1A_HUMAN Antigen-presenting protein that binds self and non-self lipid and glycolipid antigens and presents them to T-cell receptors on natural killer T-cells.[1] [2] [3]

Publication Abstract from PubMed

We optimized lipidomics methods to broadly detect endogenous lipids bound to cellular CD1a proteins. Whereas membrane phospholipids dominate in cells, CD1a preferentially captured sphingolipids, especially a C42, doubly unsaturated sphingomyelin (42:2 SM). The natural 42:2 SM but not the more common 34:1 SM blocked CD1a tetramer binding to T cells in all human subjects tested. Thus, cellular CD1a selectively captures a particular endogenous lipid that broadly blocks its binding to TCRs. Crystal structures show that the short cellular SMs stabilized a triad of surface residues to remain flush with CD1a, but the longer lipids forced the phosphocholine group to ride above the display platform to hinder TCR approach. Whereas nearly all models emphasize antigen-mediated T cell activation, we propose that the CD1a system has intrinsic autoreactivity and is negatively regulated by natural endogenous inhibitors selectively bound in its cleft. Further, the detailed chemical structures of natural blockers could guide future design of therapeutic blockers of CD1a response.

CD1a selectively captures endogenous cellular lipids that broadly block T cell response.,Cotton RN, Wegrecki M, Cheng TY, Chen YL, Veerapen N, Le Nours J, Orgill DP, Pomahac B, Talbot SG, Willis R, Altman JD, de Jong A, Van Rhijn I, Clark RA, Besra GS, Ogg G, Rossjohn J, Moody DB J Exp Med. 2021 Jul 5;218(7):e20202699. doi: 10.1084/jem.20202699. Epub 2021 May , 7. PMID:33961028[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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Citations
7 reviews cite this structure
Rumpret et al. (2022)
No citations found

See Also

References

  1. Salamero J, Bausinger H, Mommaas AM, Lipsker D, Proamer F, Cazenave JP, Goud B, de la Salle H, Hanau D. CD1a molecules traffic through the early recycling endosomal pathway in human Langerhans cells. J Invest Dermatol. 2001 Mar;116(3):401-8. PMID:11231314 doi:1264
  2. Vincent MS, Xiong X, Grant EP, Peng W, Brenner MB. CD1a-, b-, and c-restricted TCRs recognize both self and foreign antigens. J Immunol. 2005 Nov 15;175(10):6344-51. PMID:16272286
  3. Sloma I, Zilber MT, Vasselon T, Setterblad N, Cavallari M, Mori L, De Libero G, Charron D, Mooney N, Gelin C. Regulation of CD1a surface expression and antigen presentation by invariant chain and lipid rafts. J Immunol. 2008 Jan 15;180(2):980-7. PMID:18178838
  4. Cotton RN, Wegrecki M, Cheng TY, Chen YL, Veerapen N, Le Nours J, Orgill DP, Pomahac B, Talbot SG, Willis R, Altman JD, de Jong A, Van Rhijn I, Clark RA, Besra GS, Ogg G, Rossjohn J, Moody DB. CD1a selectively captures endogenous cellular lipids that broadly block T cell response. J Exp Med. 2021 Jul 5;218(7):e20202699. PMID:33961028 doi:10.1084/jem.20202699

Contents


PDB ID 7kp0

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