Disease relevance of PEX1

• The poly[(R)-3-hydroxyalkanoate] (PHA) synthase gene (phaC(Ac)) of Aeromonas caviae FA440 was modified by adding a peroxisome targeting signal encoding the last 10 amino acids at the carboxyl-terminal of spinach glycolate oxidase [1].

High impact information on PEX1

• We previously isolated an Arabidopsis: peroxisome-deficient ped2 mutant by its resistance to 2,4-dichlorophenoxybutyric acid [2].
• Stress induces peroxisome biogenesis genes [3].
• We conclude that citrate is exported from the peroxisome during fatty acid respiration, whereas in yeast, acetylcarnitine is exported [4].
• This mutant displays sucrose-dependent seedling development and reduced lateral root production, characteristics of plant peroxisome malfunction [5].
• Requirement of the C3HC4 zinc RING finger of the Arabidopsis PEX10 for photorespiration and leaf peroxisome contact with chloroplasts [6].

Biological context of PEX1

• The ultrastructural knockout phenotype of AthPEX10p suggests that this protein in Arabidopsis is essential for peroxisome, oleosome, and protein transport vesicle formation [7].
• AthPEX10, a nuclear gene essential for peroxisome and storage organelle formation during Arabidopsis embryogenesis [7].
• We show that pex12 null mutants are developmentally arrested during early embryogenesis, and that the embryo-lethal phenotype can be rescued by overexpression of the PEX12-cyan fluorescent protein fusion protein, which targets to the peroxisome [8].
• Peroxisome targeting of AtCPK1-GFP was disrupted by a deletion of two potential N-terminal acylation sites [9].
• To identify unknown proteins from plant peroxisomes, the Arabidopsis genome was screened for proteins with putative major or minor peroxisome targeting signals type 1 or 2 (PTS1 or PTS2), as defined previously (Reumann S [2004] Plant Physiol 135: 783-800) [10].

Anatomical context of PEX1

• We conclude that KATs and ACATs are present in the cytosol and peroxisome, but are not found in mitochondria [11].
• Although AtSOX lacks a typical peroxisome-targeting signal, in vitro assays established that it is imported into peroxisomes [12].
• They were found peripherally associated with peroxisome and ER membranes but not as covalently bound subunits of AtPex16p [13].
• The R. communis enzyme would therefore appear to possess an additional glyoxysome/peroxisome targeting signal that is lacking in the B. napus protein [14].
• In transient onion epidermis assay and in transgenic Arabidopsis plants, an interference with the actin cytoskeleton resulted in progressive loss of saltatory movement followed by the aggregation and a complete cessation of peroxisome motility within 30 min of drug application [15].

Associations of PEX1 with chemical compounds

• Results suggest that lipids can be used as a source of carbon for respiration in germinating oilseeds and that products of fatty acid catabolism can pass from the peroxisome to the mitochondrion independently of the glyoxylate cycle [16].
• The C18 JA precursor 12-oxo-phytodienoic acid (OPDA) is converted in the peroxisome to 3-oxo-2-(2'-[Z]-pentenyl)cyclopentane-1-octanoic acid (OPC-8:0), which subsequently undergoes three rounds of beta-oxidation to yield JA [17].
• A C-terminal dilysine motif, present in AtPex11c, -d and -e, was not necessary for AtPex11d-induced peroxisome elongation [18].
• Analysis of mfp2-1 seedlings revealed that seed storage lipid was catabolized more slowly, long-chain acyl-CoA substrates accumulated and there was an increase in peroxisome size [19].
• Requirement for 3-ketoacyl-CoA thiolase-2 in peroxisome development, fatty acid beta-oxidation and breakdown of triacylglycerol in lipid bodies of Arabidopsis seedlings [20].

Other interactions of PEX1

• The Arabidopsis peroxisomal targeting signal type 2 receptor PEX7 is necessary for peroxisome function and dependent on PEX5 [21].
• PEX10 encodes an integral membrane protein required for peroxisome biogenesis in mammals and yeast [22].
• The green fluorescent protein-SSE1 colocalizes with the red fluorescent protein (RFP)-labeled peroxisomal markers RFP-peroxisome targeting signal 1 and peroxisome targeting signal 2-RFP in transgenic Arabidopsis [23].
• Expression of PMP22 is not associated with a specific peroxisome type, as it is detected in seeds and throughout postgerminative growth as cotyledon peroxisomes undergo conversion from glyoxysomes to leaf-type peroxisomes [24].
• We propose that the peroxisome is one of the cargos translocated by MYA2 on actin filaments [25].

References