Functional Dissection of the Transmembrane Domains of the Transporter Associated with Antigen Processing (TAP)*

The transporter associated with antigen processing (TAP1/2) translocates cytosolic peptides of proteasomal degradation into the endoplasmic reticulum (ER) lumen. A peptide-loading complex of tapasin, major histocompatibility complex class I, and several auxiliary factors is assembled at the transporter to optimize antigen display to cytotoxic T-lymphocytes at the cell surface. The heterodimeric TAP complex has unique N-terminal domains in addition to a 6 + 6-transmembrane segment core common to most ABC transporters. Here we provide direct evidence that this core TAP complex is sufficient for (i) ER targeting, (ii) heterodimeric assembly within the ER membrane, (iii) peptide binding, (iv) peptide transport, and (v) specific inhibition by the herpes simplex virus protein ICP47 and the human cytomegalovirus protein US6. We show for the first time that the translocation pore of the transporter is composed of the predicted TM-(5–10) of TAP1 and TM-(4–9) of TAP2. Moreover, we demonstrate that the N-terminal domains of TAP1 and TAP2 are essential for recruitment of tapasin, consequently mediating assembly of the macromolecular peptide-loading complex.

[1]  J. Neefjes,et al.  Selective and ATP-dependent translocation of peptides by the MHC-encoded transporter. , 1993, Science.

[2]  R. Tampé,et al.  A sequential model for peptide binding and transport by the transporters associated with antigen processing. , 1994, Immunity.

[3]  R. Tampé,et al.  Functional expression and purification of the ABC transporter complex associated with antigen processing (TAP) in insect cells , 1994, FEBS letters.

[4]  P. van Endert,et al.  Characteristics of peptide and major histocompatibility complex class I/beta 2-microglobulin binding to the transporters associated with antigen processing (TAP1 and TAP2). , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[5]  P. A. Peterson,et al.  A viral inhibitor of peptide transporters for antigen presentation , 1995, Nature.

[6]  M. Nijenhuis,et al.  Multiple regions of the transporter associated with antigen processing (TAP) contribute to its peptide binding site. , 1996, Journal of immunology.

[7]  P. Cresswell,et al.  Roles for calreticulin and a novel glycoprotein, tapasin, in the interaction of MHC class I molecules with TAP. , 1996, Immunity.

[8]  M Nijenhuis,et al.  Identification of a contact region for peptide on the TAP1 chain of the transporter associated with antigen processing. , 1996, Journal of immunology.

[9]  P. A. Peterson,et al.  Molecular mechanism and species specificity of TAP inhibition by herpes simplex virus ICP47. , 1996, The EMBO journal.

[10]  Karl Kuchler,et al.  Unusual Secretory Pathways: From Bacteria to Man , 2013, Molecular Biology Intelligence Unit.

[11]  P. A. Peterson,et al.  The ER-luminal domain of the HCMV glycoprotein US6 inhibits peptide translocation by TAP. , 1997, Immunity.

[12]  R. Tampé,et al.  A critical role for tapasin in the assembly and function of multimeric MHC class I-TAP complexes. , 1997, Science.

[13]  U. Koszinowski,et al.  A viral ER-resident glycoprotein inactivates the MHC-encoded peptide transporter. , 1997, Immunity.

[14]  R. Tampé,et al.  The active domain of the herpes simplex virus protein ICP47: a potent inhibitor of the transporter associated with antigen processing. , 1997, Journal of molecular biology.

[15]  P. Cresswell,et al.  Regulation of MHC class I heterodimer stability and interaction with TAP by tapasin , 1997, Immunogenetics.

[16]  P. Cresswell,et al.  The human cytomegalovirus US6 glycoprotein inhibits transporter associated with antigen processing-dependent peptide translocation. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[17]  R. Tampé,et al.  The Transporters Associated with Antigen Processing (TAP) , 1997 .

[18]  P. Cresswell,et al.  Mechanisms of MHC class I--restricted antigen processing. , 1998, Annual review of immunology.

[19]  P. Cresswell,et al.  Soluble tapasin restores MHC class I expression and function in the tapasin-negative cell line .220. , 1998, Immunity.

[20]  M. Knittler,et al.  Nucleotide binding by TAP mediates association with peptide and release of assembled MHC class I molecules , 1999, Current Biology.

[21]  P. A. Peterson,et al.  Retention of empty MHC class I molecules by tapasin is essential to reconstitute antigen presentation in invertebrate cells , 1999, The EMBO journal.

[22]  P. van Endert,et al.  Tapasin Enhances Assembly of Transporters Associated with Antigen Processing-dependent and -independent Peptides with HLA-A2 and HLA-B27 Expressed in Insect Cells* , 1999, The Journal of Biological Chemistry.

[23]  J. Neefjes,et al.  Membrane topology and dimerization of the two subunits of the transporter associated with antigen processing reveal a three-domain structure. , 1999, Journal of immunology.

[24]  P. Cresswell,et al.  The N‐terminal region of tapasin is required to stabilize the MHC class I loading complex , 1999, European journal of immunology.

[25]  R. Tampé,et al.  Function of the transport complex TAP in cellular immune recognition. , 1999, Biochimica et biophysica acta.

[26]  J. McCluskey,et al.  Tapasin-Mediated Retention and Optimization of Peptide Ligands During the Assembly of Class I Molecules1 , 2000, The Journal of Immunology.

[27]  D. Clarke,et al.  The Packing of the Transmembrane Segments of Human Multidrug Resistance P-glycoprotein Is Revealed by Disulfide Cross-linking Analysis* , 2000, The Journal of Biological Chemistry.

[28]  Jacques Neefjes,et al.  Head–head/tail–tail relative orientation of the pore-forming domains of the heterodimeric ABC transporter TAP , 2000, Current Biology.

[29]  J. McCluskey,et al.  Distinct Functions of Tapasin Revealed by Polymorphism in MHC Class I Peptide Loading1 , 2000, The Journal of Immunology.

[30]  P. van Endert,et al.  A Region of Tapasin That Affects Ld Binding and Assembly1 , 2001, The Journal of Immunology.

[31]  P. Lehner,et al.  The human cytomegalovirus gene product US6 inhibits ATP binding by TAP , 2001, The EMBO journal.

[32]  R. Tampé,et al.  Molecular Mechanism and Structural Aspects of Transporter Associated with Antigen Processing Inhibition by the Cytomegalovirus Protein US6* , 2001, The Journal of Biological Chemistry.

[33]  J. Solheim,et al.  The interface between tapasin and MHC class I , 2002, Immunologic research.

[34]  James McCluskey,et al.  Optimization of the MHC class I peptide cargo is dependent on tapasin. , 2002, Immunity.

[35]  F. Momburg,et al.  HLA-DM, HLA-DO and tapasin: functional similarities and differences. , 2002, Current opinion in immunology.

[36]  P. Lapinski,et al.  Tapasin Interacts with the Membrane-spanning Domains of Both TAP Subunits and Enhances the Structural Stability of TAP1·TAP2 Complexes* , 2002, The Journal of Biological Chemistry.

[37]  A. Babenko,et al.  SUR-dependent Modulation of KATP Channels by an N-terminal KIR6.2 Peptide , 2002, The Journal of Biological Chemistry.

[38]  O. Mandelboim,et al.  Recruitment of MHC Class I Molecules by Tapasin into the Transporter Associated with Antigen Processing-Associated Complex Is Essential for Optimal Peptide Loading , 2002, The Journal of Immunology.

[39]  S. Powis,et al.  Interactions formed by individually expressed TAP1 and TAP2 polypeptide subunits , 2002, Immunology.

[40]  R. Tampé,et al.  Peptides Induce ATP Hydrolysis at Both Subunits of the Transporter Associated with Antigen Processing* , 2003, Journal of Biological Chemistry.

[41]  T. Elliott,et al.  Assembly and export of MHC class I peptide ligands. , 2003, Current opinion in immunology.

[42]  D. Logothetis,et al.  N‐terminal transmembrane domain of the SUR controls trafficking and gating of Kir6 channel subunits , 2003, The EMBO journal.

[43]  E. Hewitt.  The MHC class I antigen presentation pathway: strategies for viral immune evasion , 2003, Immunology.

[44]  F. Momburg,et al.  A major role for tapasin as a stabilizer of the TAP peptide transporter and consequences for MHC class I expression , 2003, European journal of immunology.

[45]  Geoffrey Chang,et al.  Structure of MsbA from Vibrio cholera: a multidrug resistance ABC transporter homolog in a closed conformation. , 2003, Journal of molecular biology.

[46]  K. Ahn,et al.  An Essential Function of Tapasin in Quality Control of HLA-G Molecules* , 2003, The Journal of Biological Chemistry.

[47]  R. Tampé,et al.  Functional cysteine‐less subunits of the transporter associated with antigen processing (TAP1 and TAP2) by de novo gene assembly , 2003, FEBS letters.

[48]  P. Cresswell,et al.  Tapasin Is a Facilitator, Not an Editor, of Class I MHC Peptide Binding 1 , 2003, The Journal of Immunology.