Major basic protein

Proteoglycan 2, bone marrow (natural killer cell activator, eosinophil granule major basic protein)
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1H8U, 2BRS, 4QXX
Identifiers
Symbols	PRG2 ; BMPG; MBP; MBP1
External IDs	OMIM: 605601 MGI: 103294 HomoloGene: 2044 GeneCards: PRG2 Gene
Gene ontology Molecular function • heparin binding • carbohydrate binding Cellular component • extracellular region • transport vesicle • extracellular exosome Biological process • defense response to nematode • immune response • negative regulation of interleukin-10 production • positive regulation of interleukin-4 production • regulation of cytokine biosynthetic process • defense response to bacterium Sources: Amigo / QuickGO
RNA expression pattern
File:PBB GE PRG2 211743 s at tn.png
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	5553	19074
Ensembl	ENSG00000186652	ENSMUSG00000027073
UniProt	P13727	Q61878
RefSeq (mRNA)	NM_001243245	NM_008920
RefSeq (protein)	NP_001230174	NP_032946
Location (UCSC)	Chr 11: 57.39 – 57.39 Mb	Chr 2: 84.98 – 84.98 Mb
PubMed search	[1]	[2]

Proteoglycan 2, bone marrow (natural killer cell activator, eosinophil granule major basic protein), also known as PRG2, is a protein which in humans is encoded by the PRG2 gene.

Function

The protein encoded by this gene is the predominant constituent of the crystalline core of the eosinophil granule. High levels of the proform of this protein are also present in placenta and pregnancy serum, where it exists as a complex with several other proteins including pregnancy-associated plasma protein A (PAPPA), angiotensinogen (AGT), and C3dg. This protein may be involved in antiparasitic defense mechanisms as a cytotoxin and helminthotoxin, and in immune hypersensitivity reactions. It is directly implicated in epithelial cell damage, exfoliation, and bronchospasm in allergic diseases.

PRG2 is a 117-residue protein that predominates in eosinophil granules. It is a potent enzyme against helminths and is toxic towards bacteria and mammalian cells in vitro. The eosinophil major basic protein also causes the release of histamine from mast cells and basophils, and activates neutrophils and alveolar macrophages.

Structure

Structurally the major basic protein (MBP) is similar to lectins (sugar-binding proteins), and has a fold similar to that seen in C-type lectins. However, unlike other C-type lectins (those that bind various carbohydrates in the presence of calcium), MBP does not bind either calcium or any of the other carbohydrates that this family recognize.

Instead, MBP recognises heparan sulfate proteoglycans. Two crystallographic structures of MBP have been determined.

Interactions

Major basic protein has been shown to interact with Pregnancy-associated plasma protein A.

See also

arylsulfatase

External links

• Eosinophil Major Basic Protein at the US National Library of Medicine Medical Subject Headings (MeSH)