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Dimerization of small integral membrane protein 1 promotes cell surface presentation of the Vel blood group epitope
Author(s) -
Kelley Liam P.,
Nylander Anja,
Arnaud Lionel,
Schmoker Anna M.,
St. Clair Riley M.,
Gleason Lindsey A.,
Souza Jessica M.,
Storry Jill R.,
Olsson Martin L.,
Ballif Bryan A.
Publication year - 2020
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.13726
Subject(s) - epitope , transmembrane domain , transmembrane protein , mutant , extracellular , glycophorin , chemistry , integral membrane protein , flow cytometry , band 3 , context (archaeology) , antigen , amino acid , microbiology and biotechnology , biochemistry , membrane protein , biology , membrane , genetics , gene , paleontology , receptor
The Vel blood group antigen is carried on the short extracellular segment of the 78‐amino‐acid‐long, type II transmembrane protein SMIM1 of unknown function. Here, using biochemical analysis and flow cytometry of cells expressing wild‐type and mutant alleles of SMIM1, we demonstrate that dimerization of SMIM1 promotes cell surface display of the Vel epitope. We show that SMIM1 dimerization is mediated both by an extracellular Cys77‐dependent, homomeric disulfide linkage and via a GxxxG helix–helix interaction motif in the transmembrane domain. These results provide important context for the observed variability in reactivity patterns of clinically important anti‐Vel identified in patient sera.