$VAR1 = undef;

Summary for peptidase A22.003: impas 1 peptidase

Names
MEROPS Name	impas 1 peptidase
Other names	AtSPP (Arabidopsis thaliana), HM13 g.p. (Homo sapiens), IMP1, intramembrane protease 1, minor histocompatibility antigen H13, CG11840 g. p. (Drosophila melanogaster), Shanti protein (Drosophila melanogaster), signal peptide peptidase, SPP peptidase, PSH3, presenilin homologue-3

Domain architecture

MEROPS Classification
Classification	Clan AD >> Subclan (none) >> Family A22 >> Subfamily B >> A22.003
Holotype	impas 1 peptidase (Homo sapiens), Uniprot accession Q8TCT9 (peptidase unit: 1-377), MERNUM MER0019701
History	Identifier created: MEROPS 6.0 (30 August 2002)

Activity
Catalytic type	Aspartic
NC-IUBMB	Not yet included in IUBMB recommendations.
Activity status	human: active (Lemberg & Martoglio, 2002) mouse: active (Lemberg & Martoglio, 2002)
Physiology	Impas 1 endopeptidase is one of the signal peptide peptidases. It can cleave signal peptides within their transmembrane region. It is essential for the generation of signal peptide-derived HLA-E epitopes in humans and is exploited by hepatitis C virus for processing of the viral polyprotein (Lemberg et al., 2002). Impas 1 endopeptidase (termed signal peptide peptidase) is essential for embryonic development in Drosophila (Casso et al., 2005).
Pharmaceutical relevance	Impas 1 endopeptidase is of pharmaceutical interest because it may be affected by inhibitors of gamma-secretase, and the consequences of this would need to be considered if such inhibitors were developed as drugs (Weihofen et al., 2003).
Other databases	WIKIPEDIA	http://en.wikipedia.org/wiki/HM13