bone marrow proteoglycan; BMPG; proteoglycan 2; contains: eosinophil granule major basic protein; EMBP; MBP; pregnancy-associated major basic protein (PRG2, MBP)

Function

• cytotoxin & helminth toxin
• also induces non-cytolytic histamine release from basophils
• role in parasitic infection defense mechanisms & in immune hypersensitivity reactions
• proform acts as a proteinase inhibitor, reducing activity of PAPPA
• nitrated
• in pregnancy serum, the proform exists as a disulfide-linked 2:2 heterotetramer with PAPPA, as a disulfide-linked 2:2 heterotetramer with AGT, & as a complex (probably a 2:2:2 heterohexamer) with AGT & C3dg
• binds heparin
• does not bind Ca+2

Structure

• contains 1 C-type lectin domain

Compartment

• bone marrow proteoglycan: secreted
• the proform is secreted
• eosinophil granule major basic protein:
  • cytoplasmic vesicle, secretory vesicle
• mature protein is found in the matrix of the eosinophil's large specific granule (crystalloid core)

Expression

• high levels of the proform in placenta & pregnancy serum
• in placenta, localized to X cells of septa & anchoring villi
• lower levels in a variety of other tissues including kidney, myometrium, endometrium, ovaries, breast, prostate, bone marrow & colon
• levels of the proform increase in serum & placenta during pregnancy

More general terms

• secreted protein
• glycoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5553
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5553
• OMIM: https://mirror.omim.org/entry/605601
• UniProt: http://www.uniprot.org/uniprot/P13727.html