Major basic protein

Eosinophil major basic protein, often shortened to major basic protein (MBP; also called proteoglycan 2 (PRG2)) is encoded in humans by the PRG2 gene.^[5]

PRG2
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1H8U, 2BRS, 4QXX
Identifiers
Aliases	PRG2, BMPG, MBP, MBP1, proteoglycan 2, bone marrow (natural killer cell activator, eosinophil granule major basic protein), proMBP, proteoglycan 2, pro eosinophil major basic protein
External IDs	OMIM: 605601; MGI: 103294; HomoloGene: 2044; GeneCards: PRG2; OMA:PRG2 - orthologs
Gene location (Human) Chr. Chromosome 11 (human)[1] Band 11q12.1 Start 57,386,780 bp[1] End 57,390,650 bp[1]
Gene location (Mouse) Chr. Chromosome 2 (mouse)[2] Band 2 D|2 49.45 cM Start 84,810,805 bp[2] End 84,813,976 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in placenta bone marrow bone marrow cells right lobe of liver skin of leg subcutaneous adipose tissue spleen skin of abdomen monocyte blood Top expressed in tibiofemoral joint granulocyte fetal liver hematopoietic progenitor cell bone marrow embryo embryo ankle joint spleen human fetus vestibular membrane of cochlear duct More reference expression data BioGPS More reference expression data
Gene ontology Molecular function heparin binding carbohydrate binding extracellular matrix structural constituent conferring compression resistance Cellular component extracellular region transport vesicle cytoplasmic vesicle extracellular exosome ficolin-1-rich granule lumen collagen-containing extracellular matrix Biological process defense response to bacterium immune system process defense response to nematode negative regulation of interleukin-10 production positive regulation of interleukin-4 production immune response neutrophil degranulation Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 5553 19074 Ensembl ENSG00000186652 ENSMUSG00000027073 UniProt P13727 Q61878 RefSeq (mRNA) NM_002728 NM_001243245 NM_001302926 NM_001302927 NM_008920 RefSeq (protein) NP_001230174 NP_001289855 NP_001289856 NP_002719 NP_032946 Location (UCSC) Chr 11: 57.39 – 57.39 Mb Chr 2: 84.81 – 84.81 Mb PubMed search [3] [4]
Wikidata
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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 helmintho-toxin, and in immune hypersensitivity reactions. It is directly implicated in epithelial cell damage, exfoliation, and bronchospasm in allergic diseases.^[5]

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.^[6][7]

Interactions

Major basic protein has been shown to interact with pregnancy-associated plasma protein A.^[8][9][10]

See also

• Arylsulfatase