LNPEP
Function
Release of an N-terminal amino acid, cleaves before cysteine, leucine as well as other amino acids. Degrades peptide hormones such as oxytocin, vasopressin and angiotensin III, and plays a role in maintaining homeostasis during pregnancy. May be involved in the inactivation of neuronal peptides in the brain. Cleaves Met-enkephalin and dynorphin. Binds angiotensin IV and may be the angiotensin IV receptor in the brain.
Post-translational modifications
The pregnancy serum form is derived from the membrane-bound form by proteolytic processing.
N-glycosylated.
Sequence Similarities
Belongs to the peptidase M1 family.
Tissue Specificity
Highly expressed in placenta, heart, kidney and small intestine. Detected at lower levels in neuronal cells in the brain, in skeletal muscle, spleen, liver, testes and colon.
Cellular localization
- Cell membrane
- Single-pass type II membrane protein
- In brain only the membrane-bound form is found. The protein resides in intracellular vesicles together with GLUT4 and can then translocate to the cell surface in response to insulin and/or oxytocin. Localization may be determined by dileucine internalization motifs, and/or by interaction with tankyrases.
- Leucyl-cystinyl aminopeptidase, pregnancy serum form
- Secreted
- During pregnancy serum levels are low in the first trimester, rise progressively during the second and third trimester and decrease rapidly after parturition.
Alternative names
OTASE, LNPEP, Leucyl-cystinyl aminopeptidase, Cystinyl aminopeptidase, Insulin-regulated membrane aminopeptidase, Insulin-responsive aminopeptidase, Oxytocinase, Placental leucine aminopeptidase, IRAP, OTase, P-LAP