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PACAP

Function

Associates with immunoglobulin M (IgM) heavy and light chains and promotes IgM assembly and secretion. May exert its effect by acting as a molecular chaperone or as an oxidoreductase as it displays a low level of oxidoreductase activity (By similarity). Isoform 2 may be involved in regulation of apoptosis. Helps to diversify peripheral B-cell functions by regulating Ca(2+) stores, antibody secretion and integrin activation.

Acts as a hormone-regulated adipokine/proinflammatory cytokine that is implicated in causing chronic inflammation, affecting cellular expansion and blunting insulin response in adipocytes. May have a role in the onset of insulin resistance.

Post-translational modifications

Forms an interchain disulfide bond with IgM monomers.

Sequence similarities

Belongs to the MZB1 family.

Tissue specificity

Widely expressed with highest levels in adult brain, small intestine and lymphoid tissues such as thymus and spleen. Expression is frequently lower in intestinal-type gastric cancer. In obese patients, more abundant in omental than in subcutaneous fat.

Cellular localization

  • Isoform 1
  • Endoplasmic reticulum lumen
  • Secreted
  • Isoform 2
  • Cytoplasm
  • Diffuse granular localization in the cytoplasm surrounding the nucleus (PubMed:11350957).

Alternative names

  • Marginal zone B- and B1-cell-specific protein
  • Mesenteric estrogen-dependent adipose 7
  • Plasma cell-induced resident endoplasmic reticulum protein
  • Proapoptotic caspase adapter protein
  • MEDA-7
  • Plasma cell-induced resident ER protein
  • pERp1
  • MZB1
  • MEDA7
  • PACAP
  • HSPC190

Target type

Proteins

Molecular weight

20694Da