Legumain

The Mammalian Legumain, also known as LGMN, also called asparaginyl endopeptidase (AEP), is a cysteine protease belonging to peptidase family C13 with a strict specificity for hydrolysis of asparaginyl bonds. Known previously only from plants and invertebrates, Legumain is discovered as a lysosomal endopeptidase in mammals. Mammalian Legumain is a cysteine endopeptidase, inhibited by iodoacetamide and maleimides, but unaffected by compound E64. The Mammalian Legumain is involved in the processing of bacterial peptides and endogenous proteins for MHC class II presentation in the lysosomal/endosomal systems. Legumain has been observed to be highly expressed in several types of solid tumors. It was demonstrated in membrane-associated vesicles concentrated at the invadopodia of tumor cells and on cell surfaces where it colocalized with integrins. Legumain was demonstrated to activate progelatinase A. Cells overexpressing Legumain possessed increased migratory and invasive activity in vitro and adopted an invasive and metastatic phenotype in vivo, inferring significance of Legumain in tumor invasion and metastasis. In addition, Legumain is expressed in both murine and human atherosclerotic lesions. The macrophage-specific expression of Legumain in vivo and ability of Legumain to induce chemotaxis of monocytes and endothelial cells in vitro suggest that Legumain may play a functional role in atherogenesis.

Legumain Related Areas

Enzyme>>Protease & Regulator>>Cysteine Protease & Regulator>>Legumain/LGMN

Immunology>>Innate Immunity>>Lysosomal Enzyme>>Legumain/LGMN

Legumain Alternative Names

Legumain, LGMN, AEP, PRSC1, LGMN1 [Homo sapiens]

Legumain, Lgmn, AEP, Prsc1, AI746452, AU022324 [Mus musculus]

Summaries for Legumain

Entrez Gene summary for LGMN:

This LGMN gene encodes a cysteine protease that has a strict specificity for hydrolysis of asparaginyl bonds. Legumain may be involved in the processing of bacterial peptides and endogenous proteins for MHC class II presentation in the lysosomal/endosomal systems. Enzyme activation is triggered by acidic pH and appears to be autocatalytic. Protein expression occurs after monocytes differentiate into dendritic cells. A fully mature, active enzyme is produced following lipopolysaccharide expression in mature dendritic cells. Overexpression of this LGMN gene may be associated with the majority of solid tumor types. This gene has a pseudogene on chromosome 13. Several alternatively spliced transcript variants have been described, but the biological validity of only two has been determined. These two variants encode the same isoform. [provided by RefSeq, Jul 2008]

OMIM - description for Legumain:

Legumain, or AEP, is a lysosomal cysteine protease that cleaves after asparagine residues. Legumain contributes to the processing of antigenic peptides and to the processing of cathepsins B (CTSB; 116810), H (CTSH; 116820), and L (CTSL1; 116880) from single-chain forms into active 2-chain forms (Liu et al., 2008).

Wikipedia summary for Legumain:

Legumain is a protein that in humans is encoded by the LGMN gene.

Human Legumain Protein General Information

 

• Protein names: Legumain
• Sequence length: 433 AA.
• Sequence similarities: Legumain belongs to the peptidase C13 family.
• Post-translational modification: Glycosylated.
• Catalytic activity: Hydrolysis of proteins and small molecule substrates at -Asn-|-Xaa- bonds.
• Subcellular location: Lysosome
• Tissue specificity: Ubiquitous. Particularly abundant in kidney, heart and placenta.

General information above from UniProt

Function for Legumain Protein

UniProtKB:

Legumain has a strict specificity for hydrolysis of asparaginyl bonds. Legumain can also cleave aspartyl bonds slowly, especially under acidic conditions. Legumain may be involved in the processing of proteins for MHC class II antigen presentation in the lysosomal/endosomal system.

Genatlas:

• Legumain has a strict specificity for hydrolysis of asparaginyl bonds (asparagine endopeptidase)
• Legumain can also cleave aspartyl bonds slowly, especially under acidic conditions
• Legumain may be involved in the processing of proteins for MHC class II antigen presentation in the lysosomal/endosomal system

Homology for human Legumain

• homolog to Schistosoma japonicum hemoglobinase
• homolog to murine Lgmn
• homolog to C.elegans W04G3.5