Cytotoxin and helminthotoxin. Also induces non-cytolytic histamine release from human basophils. Involved in antiparasitic defense mechanisms and immune hypersensitivity reactions. The proform acts as a proteinase inhibitor, reducing the activity of PAPPA.
Subcellular locations: Secreted
The proform is secreted.
Subcellular locations: Cytoplasmic vesicle, Secretory vesicle
The proform is secreted. The mature protein is found in the matrix of the eosinophil's large specific granule (crystalloid core).
Detected in plasma and urine (at protein level) ( ). Detected in placenta (at protein level) . High levels of the proform in placenta and pregnancy serum; in placenta, localized to X cells of septa and anchoring villi. Lower levels in a variety of other tissues including kidney, myometrium, endometrium, ovaries, breast, prostate, bone marrow and colon.