minor histocompatibility antigen H13; intramembrane protease 1; IMP-1; IMPAS-1; hIMP1; presenilin-like protein 3; signal peptide peptidase (HM13, H13, IMP1, PSL3, SPP, MSTP086)

Function

• catalyzes intramembrane proteolysis of some signal peptides after cleavage from a preprotein, resulting in release of the fragment from the ER membrane into the cytoplasm
• required to generate lymphocyte cell surface (HLA-E) epitopes derived from MHC class 1 signal peptides
• may play a role in graft rejection
• may be necessary for removal of the signal peptide that remains attached to the hepatitis C virus core protein after the initial proteolytic processing of the polyprotein
• role in intramembrane cleavage of PSEN1
• interacts with RNF139

Structure

• N-glycosylated
• belongs to the peptidase A22B family

Compartment

• endoplasmic reticulum membrane
• isoform 4: cell membrane
• multi-pass membrane protein

Alternative splicing

named isoforms=4

Expression

• widely expressed
• highest expression in kidney, liver, placenta, lung,
• leukocytes & small intestine
• lower expression in heart & skeletal muscle
• expressed abundantly in the CNS with highest levels in thalamus & medulla

More general terms

• presenilin-like protein
• transmembrane 7 protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=81502
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:81502
• OMIM: https://mirror.omim.org/entry/607106
• UniProt: http://www.uniprot.org/uniprot/Q8TCT9.html