PITRM1

Pitrilysin metallopeptidase 1 also known as presequence protease, mitochondrial (PreP) and metalloprotease 1 (MTP-1) is an enzyme that in humans is encoded by the PITRM1 gene. It is also sometimes called metalloprotease 1 (MP1).PreP facilitates proteostasis by utilizing an ~13300-A(3) catalytic chamber to degrade toxic peptides, including mitochondrial presequences and β-amyloid. Deficiency of PreP is found associated with Alzheimer's disease. Reduced levels of PreP via RNAi mediated knockdown have been shown to lead to defective maturation of the protein frataxin.

Pitrilysin metallopeptidase 1 also known as presequence protease, mitochondrial (PreP) and metalloprotease 1 (MTP-1) is an enzyme that in humans is encoded by the PITRM1 gene. It is also sometimes called metalloprotease 1 (MP1).PreP facilitates proteostasis by utilizing an ~13300-A(3) catalytic chamber to degrade toxic peptides, including mitochondrial presequences and β-amyloid. Deficiency of PreP is found associated with Alzheimer's disease. Reduced levels of PreP via RNAi mediated knockdown have been shown to lead to defective maturation of the protein frataxin. ===Gene=== The PITRM1 gene is located at chromosome 10q15.2, consisting of 28 exons. ===Protein=== PreP is a 117 kDa M16C enzyme that is widely expressed in human tissues. PreP is composed of PreP-N (aa 33-509) and PreP-C (aa 576-1037) domains, which are connected by an extended helical hairpin (aa 510-575). Its structure demonstrates that substrate selection by size-exclusion is a conserved mechanism in M16C proteases. ==Clinical significance== PreP is the Aβ-degrading protease in mitochondria. Immune-depletion of PreP in brain mitochondria prevents degradation of mitochondrial Aβ, and PreP activity is found diminished in AD patients. It has been reported that the loss of PreP activity is due to methionine oxidation and this study provides a rational basis for therapeutic intervention in conditions characterized by excessive oxidation of PreP. A recent study also suggests that PreP regulates islet amyloid polypeptide in beta cells. Two siblings carrying a homozygous PITRM1 missense mutation (c.548G>A, p.Arg183Gln) were reported to be associated with an autosomal recessive, slowly progressive syndrome. Clinical features include mental retardation, spinocerebellar ataxia, cognitive decline and psychosis. A mouse model hemizygous for PITRM1 displayed progressive ataxia which was suggested to be linked to brain degenerative lesions, including accumulation of Aβ‐positive amyloid deposits. Recently, two brothers from a consanguineous family presenting with childhood-onset recessive cerebellar pathology were shown to carry a homozygous mutation in PITRM1 (c.2795C>T, p.T931M). This mutation resulted in 95% reduction in PITRM1 protein. PITRM1 knockdown was shown to lead to reduced levels of mature Frataxin protein, a protein that when deficient causes Friedreich's ataxia, and may be implicated in pathology in patients carrying PITRM1 mutations.

Text derived from https://en.wikipedia.org/w/index.php?oldid=1369642466 under CC BY-SA 4.0; modifications have been made.