Legumain

Legumain is a highly specific asparaginyl endopeptidase located in the lysosome. Its precursor zymogen consists of three parts, the signal peptide, the precursor peptide and the active site containing the mature protease. Studies have sequenced mammalian legumain, in which the relative molecular mass of pig Legumain is about 34 x 103, and the relative molecular mass after deglycosylation is 31 X103; the coding gene of human Legumain is located on human chromosome 14q32. The relative molecular mass is 49x103, which consists of 433 amino acid residues. After deglycosylation, the relative molecular mass of mature Legumain with bioactivity is 31 x103; the relative molecular mass of mouse Legumain is 35x10%. Under normal conditions, Legumain is not expressed or only expressed at low levels in mammals, only activated under acidic conditions (pH = 3 to 6), and becomes unstable when pH> 6.
Asparagine endopeptidase (LGUM) is a new member of the cysteine protease family. It was first discovered in plant beans and cowpeas, and the researchers later found that legumain is expressed in vertebrates and mammals. Like other cathepsins, legumain is mainly localized in the lysosomes of cells and involved in the degradation of various physiological processes such as matrix proteins.
Studies have shown that the legumain gene is highly expressed in a variety of tumor tissues, and the high expression of legumain is closely related to the tumor development and tumor invasion and metastasis. As a newly discovered protease closely related to tumor invasion and metastasis, Legumain plays an important role in tumor cells and tumor microenvironment, further elucidating the role and mechanism of Legumain in tumor growth and metastasis and the regulation mechanism of Legumain expression. It can provide new targets for the diagnosis, treatment and prevention of malignant tumors.

This gene encodes a cysteine protease that has a strict specificity for hydrolysis of asparaginyl bonds. This enzyme 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 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]LGMN (Legumain) is a Protein Coding gene. Diseases associated with LGMN include Schistosomiasis. Among its related pathways are Metabolism and Activated TLR4 signalling. Gene Ontology (GO) annotations related to this gene include peptidase activity and cysteine-type endopeptidase activity. An important paralog of this gene is PIGK.Has a strict specificity for hydrolysis of asparaginyl bonds. Can also cleave aspartyl bonds slowly, especially under acidic conditions. Required for normal lysosomal protein degradation in renal proximal tubules. Required for normal degradation of internalized EGFR. Plays a role in the regulation of cell proliferation via its role in EGFR degradation (By similarity). May be involved in the processing of proteins for MHC class II antigen presentation in the lysosomal/endosomal system.