Tapasin

From Wikipedia, the free encyclopedia

TAP binding protein (tapasin)

Identifiers

TAPBP; NGS17; TAPA; TPN; TPSN

External IDs

OMIM: 601962 MGI: 1201689 HomoloGene: 2401

Gene ontology
Molecular Function:	• peptide antigen-transporting ATPase activity • MHC class I protein binding • peptide antigen binding • TAP1 binding • TAP2 binding • unfolded protein binding
Cellular Component:	• Golgi membrane • endoplasmic reticulum • endoplasmic reticulum membrane • microsome • membrane • integral to membrane • MHC class I peptide loading complex
Biological Process:	• protein complex assembly • retrograde vesicle-mediated transport, Golgi to ER • defense response • immune response • antigen processing and presentation of endogenous peptide antigen via MHC class I • peptide antigen stabilization

RNA expression pattern

More reference expression data

Orthologs

Human

Mouse

Refseq

NM_003190 (mRNA)
NP_003181 (protein)

NM_001025313 (mRNA)
NP_001020484 (protein)

Location

Chr 6: 33.38 - 33.39 Mb

Chr 17: 33.53 - 33.54 Mb

Pubmed search

[1]

[2]

TAP binding protein (tapasin), also known as TAPBP, is a human gene.^[1]

This gene encodes a transmembrane glycoprotein which mediates interaction between newly assembled major histocompatibility complex (MHC) class I molecules and the transporter associated with antigen processing (TAP), which is required for the transport of antigenic peptides across the endoplasmic reticulum membrane. This interaction is essential for optimal peptide loading on the MHC class I molecule. Up to four complexes of MHC class I and this protein may be bound to a single TAP molecule. This protein contains a C-terminal double-lysine motif (KKKAE) known to maintain membrane proteins in the endoplasmic reticulum. This gene lies within the major histocompatibility complex on chromosome 6. Alternative splicing results in three transcript variants encoding different isoforms.^[1]

Tapasin is a MHC class I antigen processing molecule present in the lumen of the endoplasmic reticulum. It plays an important role in the maturation of MHC class I molecules in the ER lumen. This protein is one component of the peptide loading complex, and can be found associated with MHC class I molecules after the MHC class I heavy chain has associated with the Beta₂ microglobulin. Tapasin recruits MHC class I molecules to the TAP peptide transporter, and also enhances loading of MHC class I with high affinity peptides. Following loading of MHC class I with a high affinity ligand the interaction between tapasin and MHC class I disappears.^[2]

1 See also
2 References
3 Further reading
4 External links

[edit] See also

Transporter associated with antigen processing ("TAP")

[edit] References

^ ^a ^b Entrez Gene: TAPBP TAP binding protein (tapasin).
^ Zhang Y, Williams DB (2006). "Assembly of MHC class I molecules within the endoplasmic reticulum". Immunol. Res. 35 (1-2): 151–62. doi:10.1385/IR:35:1:151. PMID 17003517.

[edit] Further reading

Turnquist HR, Vargas SE, Schenk EL, et al. (2002). "The interface between tapasin and MHC class I: identification of amino acid residues in both proteins that influence their interaction.". Immunol. Res. 25 (3): 261–9. PMID 12018464.
Momburg F, Tan P (2002). "Tapasin-the keystone of the loading complex optimizing peptide binding by MHC class I molecules in the endoplasmic reticulum.". Mol. Immunol. 39 (3-4): 217–33. PMID 12200052.
Dissemond J, Kothen T, Mörs J, et al. (2004). "Downregulation of tapasin expression in progressive human malignant melanoma.". Arch. Dermatol. Res. 295 (2): 43–9. doi:10.1007/s00403-003-0393-8. PMID 12682852.
Paulsson K, Wang P (2003). "Chaperones and folding of MHC class I molecules in the endoplasmic reticulum.". Biochim. Biophys. Acta 1641 (1): 1–12. PMID 12788224.
Andersson B, Wentland MA, Ricafrente JY, et al. (1996). "A "double adaptor" method for improved shotgun library construction.". Anal. Biochem. 236 (1): 107–13. doi:10.1006/abio.1996.0138. PMID 8619474.
Sadasivan B, Lehner PJ, Ortmann B, et al. (1996). "Roles for calreticulin and a novel glycoprotein, tapasin, in the interaction of MHC class I molecules with TAP.". Immunity 5 (2): 103–14. PMID 8769474.
Lewis JW, Neisig A, Neefjes J, Elliott T (1997). "Point mutations in the alpha 2 domain of HLA-A2.1 define a functionally relevant interaction with TAP.". Curr. Biol. 6 (7): 873–83. PMID 8805302.
Yu W, Andersson B, Worley KC, et al. (1997). "Large-scale concatenation cDNA sequencing.". Genome Res. 7 (4): 353–8. PMID 9110174.
Li S, Sjögren HO, Hellman U, et al. (1997). "Cloning and functional characterization of a subunit of the transporter associated with antigen processing.". Proc. Natl. Acad. Sci. U.S.A. 94 (16): 8708–13. PMID 9238042.
Ortmann B, Copeman J, Lehner PJ, et al. (1997). "A critical role for tapasin in the assembly and function of multimeric MHC class I-TAP complexes.". Science 277 (5330): 1306–9. PMID 9271576.
Herberg JA, Sgouros J, Jones T, et al. (1998). "Genomic analysis of the Tapasin gene, located close to the TAP loci in the MHC.". Eur. J. Immunol. 28 (2): 459–67. PMID 9521053.
Lindquist JA, Jensen ON, Mann M, Hämmerling GJ (1998). "ER-60, a chaperone with thiol-dependent reductase activity involved in MHC class I assembly.". EMBO J. 17 (8): 2186–95. doi:10.1093/emboj/17.8.2186. PMID 9545232.
Herberg JA, Beck S, Trowsdale J (1998). "TAPASIN, DAXX, RGL2, HKE2 and four new genes (BING 1, 3 to 5) form a dense cluster at the centromeric end of the MHC.". J. Mol. Biol. 277 (4): 839–57. doi:10.1006/jmbi.1998.1637. PMID 9545376.
Furukawa H, Kashiwase K, Yabe T, et al. (1999). "Polymorphism of TAPASIN and its linkage disequilibria with HLA class II genes in the Japanese population.". Tissue Antigens 52 (3): 279–81. PMID 9802609.
El Ouakfaoui S, Heitz D, Paquin R, Beaulieu AD (1999). "Granulocyte-macrophage colony-stimulating factor modulates tapasin expression in human neutrophils.". J. Leukoc. Biol. 65 (2): 205–10. PMID 10088603.
Bangia N, Lehner PJ, Hughes EA, et al. (1999). "The N-terminal region of tapasin is required to stabilize the MHC class I loading complex.". Eur. J. Immunol. 29 (6): 1858–70. PMID 10382748.
Knittler MR, Alberts P, Deverson EV, Howard JC (2000). "Nucleotide binding by TAP mediates association with peptide and release of assembled MHC class I molecules.". Curr. Biol. 9 (18): 999–1008. PMID 10508608.
Li S, Paulsson KM, Chen S, et al. (2000). "Tapasin is required for efficient peptide binding to transporter associated with antigen processing.". J. Biol. Chem. 275 (3): 1581–6. PMID 10636848.
Tan P, Kropshofer H, Mandelboim O, et al. (2002). "Recruitment of MHC class I molecules by tapasin into the transporter associated with antigen processing-associated complex is essential for optimal peptide loading.". J. Immunol. 168 (4): 1950–60. PMID 11823531.
Mayer WE, Klein J (2002). "Is tapasin a modified Mhc class I molecule?". Immunogenetics 53 (9): 719–23. doi:10.1007/s00251-001-0403-y. PMID 11862402.