Summary for peptidase M01.028: aminopeptidase O

Summary Alignment Tree Sequences Sequence features Distribution Literature Human EST Mouse EST Substrates Inhibitors

 

Names
MEROPS Nameaminopeptidase O
Other namesclone MGC:31762, Mername-AA139 putative peptidase
Name and HistoryAminopeptidase O is an intracellular aminopeptidase with a preference for arginyl bonds (Diaz-Perales et al., 2005).
Domain architecture
MEROPS Classification
Classification Clan MA >> Subclan MA(E) >> Family M1 >> Subfamily (none) >> M01.028
Holotypeaminopeptidase O (Homo sapiens), Uniprot accession Q8N6M6 (peptidase unit: 394-652), MERNUM MER0019730
History Identifier created: MEROPS 6.0 (30 August 2002)
Activity
Catalytic typeMetallo
NC-IUBMBNot yet included in IUBMB recommendations.
Activity statushuman: putative
mouse: putative
SpecificityAminopeptidase O has a preference for arginyl bonds but can also release asparagine from peptides. It is also able to convert angiotensin III to angiotensin IV (Diaz-Perales et al., 2005).
Inhibitor commentsAminopeptidase O is inhibited by arphamenine A, which also inhibits aminopeptidase B and leukotriene A4 hydrolase (Diaz-Perales et al., 2005).
StructureAminopeptidase has a C-terminal extension containing an ARM-repeat domain (Diaz-Perales et al., 2005). This is a domain also found in aminopeptidase B and leukotriene A4 hydrolase, and is named after the Drosophila Armadillo protein, which is important for segment polarity. Between the peptidase and ARM-domain there is an 11-mer, basic residue-rich nucleolus location motif (Axton et al., 2008).
LocationAminopeptidase O has been localized to the nucleolus (Axton et al., 2008).
Biological aspectsIn human, aminopeptidase O is mainly expressed in the pancreas, placenta, liver, testis and heart (Diaz-Perales et al., 2005). A shorter isoform has been localized to endothelial and smooth muscle cells in both adult and embryonic blood vessels (Axton et al., 2008). The AOPEP gene also includes a cluster of microRNAs, one of which, miR-27b, has been shown to modulate expression of the Mef2c gene which encodes myocyte-specific enhancer factor 2C (Chinchilla et al., 2011). A microRNA is controlled by the same promoter as its host gene, which is also usually the source of the mRNA inhibited by complementation with the microRNA.
RNA splicingIn the mouse, a shorter isoform is generated from an alternative initiating methionine located near the start of the peptidase domain (Axton et al., 2008).
Other databases TREEFAMhttp://www.treefam.org/family/TF332004
Human genetics
Gene symbol Locus Megabases Ensembl Entrez gene Gene Cards OMIM
C9orf3 9q22.32 ENSG00000148120 84909
Mouse genetics
Gene symbol Position Megabases Ensembl Entrez gene MGI
2010111I01Rik 13:B3 ENSMUSG00000021458 72061 MGI:1919311