Efficient IgM assembly and secretion require the plasma cell induced endoplasmic reticulum protein pERp1

Research output: Contribution to journalArticle


  • Eelco Van Anken
  • Florentina Pena
  • Nicole Hafkemeijer
  • Chantal Christis
  • Edwin P. Romijn
  • Ulla Grauschopf
  • Viola M.J. Oorschot
  • Thomas Pertel
  • Sander Engels
  • Ari Ora

  • Viorica Lástun
  • Rudi Glockshuber
  • Judith Klumperman
  • Albert J.R. Heck
  • Jeremy Luban
  • Ineke Braakman

Research units

  • Utrecht University
  • University of California at San Francisco
  • CrossBeta Biosciences B.V.
  • Medical Research Council
  • Philips Research
  • Swiss Federal Institute of Technology Zurich
  • F. Hoffmann-La Roche Ltd
  • University Medical Center Utrecht
  • University of Geneva
  • Università della Svizzera italiana


Plasma cells daily secrete theirownmass in antibodies, which fold and assemble in the endoplasmic reticulum (ER). To reach these levels, cells require pERp1, a novel lymphocyte-specific small ER-resident protein, which attains expression levels as high as BiP when B cells differentiate into plasma cells. Although pERp1 has no homology with known ER proteins, it does contain a CXXC motif typical for oxidoreductases. In steady state, the CXXC cysteines are locked by two parallel disulfide bonds with a downstream C(X)6C motif, and pERp1 displays only modest oxidoreductase activity. pERp1 emerged as a dedicated folding factor for IgM, associating with both heavy and light chains and promoting assembly and secretion of mature IgM.


Original languageEnglish
Pages (from-to)17019-17024
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number40
Publication statusPublished - 6 Oct 2009
MoE publication typeA1 Journal article-refereed

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