title: The organellar peptidasome, PreP: a journey from Arabidopsis to Alzheimer's disease.
abstract: The novel peptidasome, called presequence protease, PreP, was originally identified and characterized in Arabidopsis thaliana as a mitochondrial matrix and chloroplast stroma localized metalloprotease. PreP has a function as the organellar peptide clearing protease and is responsible for degrading free targeting peptides and also other unstructured peptides up to 65 amino acid residues that might be toxic to organellar functions. PreP contains an inverted Zn-binding motif and belongs to the pitrilysin protease family. The crystal structure of AtPreP refined at 2.1 A demonstrated a unique totally enclosed large cavity of 10000 A3 that opens and closes in response to peptide binding, revealing a novel catalytic mechanism for proteolysis. Homologues of PreP have been found in yeast and human mitochondria. Interestingly, the human PreP, hPreP, is the protease that is responsible for clearing the human brain mitochondria from the toxic amyloid-beta peptide (Abeta) associated with Alzheimer's disease (AD). Accumulation of Abeta has been shown in the brain mitochondria from AD patients and mutant transgenic mice overexpressing Abeta. Here, we present a review of our present knowledge on structural and functional characteristics of PreP and discuss its mitochondrial Abeta-degrading activity in the human brain mitochondria in relation to AD.
authors.affiliation: Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden. e_glaser@dbb.su.se
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Glaser
authors.forename: Nyosha
authors.initials: N
authors.lastname: Alikhani
mesh_terms: D000544:Alzheimer Disease / Q000201:enzymology* / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000378:metabolism; D000818:Animals; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D008928:Mitochondria / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D015388:Organelles / Q000201:enzymology; D010447:Peptide Hydrolases / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013379:Substrate Specificity
chemical_list: D016229:Amyloid beta-Peptides; D029681:Arabidopsis Proteins; D010447:Peptide Hydrolases; C511107:presequence protease PreP, Arabidopsis