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

ABSTRACT: Plasma cells daily secrete their own mass 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)(6)C 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.

SUBMITTER: van Anken E 

PROVIDER: S-EPMC2761347 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature