presequence protease, mitochondrial (hPreP, pitrilysin metalloproteinase 1, metalloprotease 1, hMP1, PITRM1, KIAA1104, MP1)

Function

• ATP-independent protease
• degrades mitochondrial transit peptides after their cleavage
• also degrades other unstructured peptides
• specific for peptides in the range of 10-65 residues
• able to degrade amyloid beta A4 (APP) protein when it accumulates in mitochondrion
• preference for cleavage after small polar residues & before basic residues, without any positional preference

Cofactor: binds 1 Zn+2 per subunit

Structure

• homodimer
• disulfide bond may lock the enzyme in a closed conformation under oxidized conditions, i.e. redox regulation of enzyme
• belongs to the peptidase M16 family, PreP subfamily

Compartment

mitochondrial matrix

Alternative splicing

named isoforms=2

Expression

• widely expressed
• expressed in muscle & heart > brain, pancreas, liver, lung & placenta

More general terms

• mitochondrial protein
• metalloprotease

Database

• UniProt: http://www.uniprot.org/uniprot/Q5JRX3.html