-
Molecular and Cellular Biochemistry Jan 1997In this article, the capabilities of peroxisomal involvement in the gluconeogenetic processes of vertebrate animals are reviewed in the light of recent findings on... (Review)
Review
In this article, the capabilities of peroxisomal involvement in the gluconeogenetic processes of vertebrate animals are reviewed in the light of recent findings on peroxisomal metabolism and proliferation. It is demonstrated that the participation of this organelle affords the potential of alternative pathways for the conversion of triacylglycerols to glucose, and for the conversion of amino acids and lactate to carbohydrate. Of interest in this connection, too, is that glyoxylate may act as a key intermediate in the gluconeogenetic functions of peroxisomes in both plants and animals. In addition, a close connection between peroxisomal function and the hormonal control of gluconeogenesis has been described, with these interrelationships extending to the associated phenomena of cellular signalling, gene expression, peroxisomal proliferation, and the function of insulin-like growth factors. The metabolic advantages of some of these alternative pathways for gluconeogenesis have been detailed, and suggestions made for the further testing of their quantitative relativities.
Topics: Amino Acids; Animals; Gene Expression Regulation; Gluconeogenesis; Glyoxylates; Insulin; Lactic Acid; Microbodies; Plants; Triglycerides
PubMed: 9046033
DOI: 10.1023/a:1006879111028 -
The Journal of Biological Chemistry Nov 1998Mammalian cells typically contain hundreds of peroxisomes but can increase peroxisome abundance further in response to extracellular stimuli. We report here the...
Mammalian cells typically contain hundreds of peroxisomes but can increase peroxisome abundance further in response to extracellular stimuli. We report here the identification and characterization of two novel human peroxisomal membrane proteins, PEX11alpha and PEX11beta. Overexpression of the human PEX11beta gene alone was sufficient to induce peroxisome proliferation, demonstrating that proliferation can occur in the absence of extracellular stimuli and may be mediated by a single gene. Time course studies indicated that PEX11beta induces peroxisome proliferation through a multistep process involving peroxisome elongation and segregation of PEX11beta from other peroxisomal membrane proteins, followed by peroxisome division. Overexpression of PEX11alpha also induced peroxisome proliferation but at a much lower frequency than PEX11beta in our experimental system. The patterns of PEX11alpha and PEX11beta expression were examined in the rat, the animal in which peroxisome proliferation has been examined most extensively. Levels of PEX11beta mRNA were similar in all tissues examined and were unaffected by peroxisome-proliferating agents. Conversely, PEX11alpha mRNA levels varied widely among different tissues, were highest in tissues that are sensitive to peroxisome-proliferating agents, and were induced more than 10-fold in response to the peroxisome proliferators clofibrate and di(2-ethylhexyl) phthalate. Taken together, these data implicate PEX11beta in the constitutive control of peroxisome abundance and suggest that PEX11alpha may regulate peroxisome abundance in response to extracellular stimuli.
Topics: Amino Acid Sequence; Animals; Cell Line; DNA Primers; DNA, Complementary; Fluorescent Antibody Technique, Indirect; Fungal Proteins; Gene Expression; Humans; Membrane Proteins; Microbodies; Molecular Sequence Data; Peroxins; Rats; Sequence Homology, Amino Acid
PubMed: 9792670
DOI: 10.1074/jbc.273.45.29607 -
The Plant Journal : For Cell and... Sep 2019Although peroxisomes play a key role in plant metabolism under both normal and stressful growth conditions, the impact of drought and heat stress on the peroxisomes...
Although peroxisomes play a key role in plant metabolism under both normal and stressful growth conditions, the impact of drought and heat stress on the peroxisomes remains unknown. Quinoa represents an informative system for dissecting the impact of abiotic stress on peroxisome proliferation because it is adapted to marginal environments. Here we determined the correlation of peroxisome abundance with physiological responses and yield under heat, drought and heat plus drought stresses in eight genotypes of quinoa. We found that all stresses caused a reduction in stomatal conductance and yield. Furthermore, H O content increased under drought and heat plus drought. Principal component analysis demonstrated that peroxisome abundance correlated positively with H O content in leaves and correlated negatively with yield. Pearson correlation coefficient for yield and peroxisome abundance (r = -0.59) was higher than for commonly used photosynthetic efficiency (r = 0.23), but comparable to those for classical stress indicators such as soil moisture content (r = 0.51) or stomatal conductance (r = 0.62). Our work established peroxisome abundance as a cellular sensor for measuring responses to heat and drought stress in the genetically diverse populations. As heat waves threaten agricultural productivity in arid climates, our findings will facilitate identification of genetic markers for improving yield of crops under extreme weather patterns.
Topics: Chenopodium quinoa; Crops, Agricultural; Droughts; Gene Expression Regulation, Plant; Heat-Shock Response; Hot Temperature; Hydrogen Peroxide; Peroxisomes; Photosynthesis; Phylogeny; Plant Stomata
PubMed: 31108001
DOI: 10.1111/tpj.14411 -
PloS One Feb 2010The PEX11 family of peroxisome membrane proteins have been shown to be involved in regulation of peroxisome size and number in plant, animals, and yeast cells. We and...
The PEX11 family of peroxisome membrane proteins have been shown to be involved in regulation of peroxisome size and number in plant, animals, and yeast cells. We and others have previously suggested that peroxisome proliferation as a result of abiotic stress may be important in plant stress responses, and recently it was reported that several rice PEX11 genes were up regulated in response to abiotic stress. We sought to test the hypothesis that promoting peroxisome proliferation in Arabidopsis thaliana by over expression of one PEX11 family member, PEX11e, would give increased resistance to salt stress. We could demonstrate up regulation of PEX11e by salt stress and increased peroxisome number by both PEX11e over expression and salt stress, however our experiments failed to find a correlation between PEX11e over expression and increased peroxisome metabolic activity or resistance to salt stress. This suggests that although peroxisome proliferation may be a consequence of salt stress, it does not affect the ability of Arabidopsis plants to tolerate saline conditions.
Topics: Arabidopsis; Arabidopsis Proteins; Cell Line; Cells, Cultured; Gene Expression Regulation, Plant; Immunoblotting; Luminescent Proteins; Membrane Proteins; Microscopy, Fluorescence; Peroxins; Peroxisomes; Plants, Genetically Modified; Protein Isoforms; Salt Tolerance; Sodium Chloride; Nicotiana; Up-Regulation
PubMed: 20195524
DOI: 10.1371/journal.pone.0009408 -
Plant Signaling & Behavior Oct 2008Peroxisomes are multifunctional organelles whose abundance and metabolic activities differ depending on the species, cell type, developmental stage and prevailing...
Peroxisomes are multifunctional organelles whose abundance and metabolic activities differ depending on the species, cell type, developmental stage and prevailing environmental conditions.1 However, little is known about the signaling pathways that control these variations, especially in plants. Our laboratory recently investigated the regulatory role of light in changes in peroxisome abundance and identified a phytochrome A-dependent pathway responsible for the proliferation of peroxisomes during dark-to-light transition in Arabidopsis seedlings. Light induces peroxisome proliferation at least in part through upregulating the PEX11b gene, which encodes a peroxisomal membrane protein that mediates the early stages of peroxisome multiplication. Activation of PEX11b requires the far-red light receptor phyA, as well as the bZIP transcription factor HYH, which binds directly to the promoter of PEX11b. We conclude that during photomorphogenesis, both the import of leaf-peroxisome enzymes from the cytosol and the induction of peroxisome proliferation take place to prepare seedlings for photosynthesis and photorespiration. In addition to light, other plant peroxisome proliferators may also exert their functions by targeting members of the PEX11 gene family for transcriptional activation.
PubMed: 19704562
DOI: 10.4161/psb.3.10.5876 -
Cells Jan 2022Pex11, an abundant peroxisomal membrane protein (PMP), is required for division of peroxisomes and is robustly imported to peroxisomal membranes. We present a...
Pex11, an abundant peroxisomal membrane protein (PMP), is required for division of peroxisomes and is robustly imported to peroxisomal membranes. We present a comprehensive analysis of how the Pex11 is recognized and chaperoned by Pex19, targeted to peroxisome membranes and inserted therein. We demonstrate that Pex11 contains one Pex19-binding site (Pex19-BS) that is required for Pex11 insertion into peroxisomal membranes by Pex19, but is non-essential for peroxisomal trafficking. We provide extensive mutational analyses regarding the recognition of Pex19-BS in Pex11 by Pex19. Pex11 also has a second, Pex19-independent membrane peroxisome-targeting signal (mPTS) that is preserved among Pex11-family proteins and anchors the human HsPex11γ to the outer leaflet of the peroxisomal membrane. Thus, unlike most PMPs, Pex11 can use two mechanisms of transport to peroxisomes, where only one of them depends on its direct interaction with Pex19, but the other does not. However, Pex19 is necessary for membrane insertion of Pex11. We show that Pex11 can self-interact, using both homo- and/or heterotypic interactions involving its N-terminal helical domains. We demonstrate that Pex19 acts as a chaperone by interacting with the Pex19-BS in Pex11, thereby protecting Pex11 from spontaneous oligomerization that would otherwise cause its aggregation and subsequent degradation.
Topics: Amino Acid Sequence; Cell Proliferation; Humans; Membrane Proteins; Molecular Chaperones
PubMed: 35011719
DOI: 10.3390/cells11010157 -
Cell Biochemistry and Biophysics 2000Extensive peroxisome proliferation during growth on oleic acid, combined with the availability of excellent genetic tools, makes the dimorphic yeast, Yarrowia... (Review)
Review
Extensive peroxisome proliferation during growth on oleic acid, combined with the availability of excellent genetic tools, makes the dimorphic yeast, Yarrowia lipolytica, a powerful model system to study the molecular mechanisms involved in peroxisome biogenesis. A combined genetic, biochemical, and morphological approach has revealed that the endoplasmic reticulum (ER) plays an essential role in the assembly of functional peroxisomes in this yeast. The trafficking of some membrane proteins to the peroxisomes occurs via the ER, results in their glycosylation in the ER lumen, does not involve transit through the Golgi, and requires the products of the SEC238, SRP54, PEX1, and PEX6 genes. The authors' data suggest a model for protein import into peroxisomes via two subpopulations of ER-derived vesicles that are distinct from secretory vesicles. A kinetic analysis of the trafficking of peroxisomal proteins in vivo has demonstrated that membrane and matrix proteins are initially targeted to multiple vesicular precursors that represent intermediates in the assembly pathway of peroxisomes. The authors have also recently identified a novel cytosolic chaperone, Pex20p, that assists in the oligomerization of thiolase in the cytosol and promotes its targeting to the peroxisome. These data provide the first evidence that a chaperone-assisted folding and oligomerization of thiolase in the cytosol is required for the import of this protein into the peroxisomal matrix.
Topics: Fungal Proteins; Fungi; Gene Expression Regulation, Fungal; Peroxisomes
PubMed: 11330048
DOI: 10.1385/cbb:32:1-3:21 -
Specificity of the peroxisome proliferation response in mussels exposed to environmental pollutants.Aquatic Toxicology (Amsterdam,... Jun 2006Peroxisome proliferation has been proposed as novel biomarker of exposure to organic pollutants in aquatic organisms. Peroxisome proliferator compounds comprise a... (Comparative Study)
Comparative Study
Peroxisome proliferation has been proposed as novel biomarker of exposure to organic pollutants in aquatic organisms. Peroxisome proliferator compounds comprise a heterogeneous group of substances known for their ability to cause massive proliferation of peroxisomes and liver carcinogenesis in sensitive species such as rodents. Recently, several marine organisms (mussels and fish) have been shown as target species of peroxisome proliferators. In the present work, we aimed to investigate the specificity of the peroxisome proliferation response in mussels. For this purpose, mussels (Mytilus edulis) were exposed for three weeks to North Sea crude oil (NSO), a mixture of NSO, alkylphenols and extra PAHs (MIX), diallylphthalate (DAP), bisphenol-A (BPA) and tetrabromodiphenylether (TBDE), or transplanted for three weeks to four stations showing different copper concentrations in a copper mine. Peroxisome proliferation was assessed by measuring the activity of the peroxisomal beta-oxidation enzyme acyl-CoA oxidase (AOX) and the volume density occupied by peroxisomes (V(VP)) in the digestive gland. Mussels exposed to NSO and MIX showed significantly increased AOX activities and V(VP) compared to control animals. Significantly higher V(VP) was also found in DAP and TBDE exposed mussels. V(VP) did not vary in mussels transplanted into a copper concentration gradient. Our results confirm the usefulness and specificity of peroxisome proliferation as a suitable biomarker of exposure to organic contaminants such as oil derived hydrocarbons, phthalate plasticizers and polybrominated flame retardants in mussels.
Topics: Acyl-CoA Oxidase; Animals; Copper; Digestive System; Mytilus edulis; Organic Chemicals; Peroxisomes; Petroleum; Spectrum Analysis
PubMed: 16600397
DOI: 10.1016/j.aquatox.2006.02.016 -
Plant, Cell & Environment Oct 2020Nitric oxide (NO) and nitrosylated derivatives are produced in peroxisomes, but the impact of NO metabolism on organelle functions remains largely uncharacterised....
Nitric oxide (NO) and nitrosylated derivatives are produced in peroxisomes, but the impact of NO metabolism on organelle functions remains largely uncharacterised. Double and triple NO-related mutants expressing cyan florescent protein (CFP)-SKL (nox1 × px-ck and nia1 nia2 × px-ck) were generated to determine whether NO regulates peroxisomal dynamics in response to cadmium (Cd) stress using confocal microscopy. Peroxule production was compromised in the nia1 nia2 mutants, which had lower NO levels than the wild-type plants. These findings show that NO is produced early in the response to Cd stress and was involved in peroxule production. Cd-induced peroxisomal proliferation was analysed using electron microscopy and by the accumulation of the peroxisomal marker PEX14. Peroxisomal proliferation was inhibited in the nia1 nia2 mutants. However, the phenotype was recovered by exogenous NO treatment. The number of peroxisomes and oxidative metabolism were changed in the NO-related mutant cells. Furthermore, the pattern of oxidative modification and S-nitrosylation of the catalase (CAT) protein was changed in the NO-related mutants in both the absence and presence of Cd stress. Peroxisome-dependent signalling was also affected in the NO-related mutants. Taken together, these results show that NO metabolism plays an important role in peroxisome functions and signalling.
Topics: Arabidopsis; Blotting, Western; Cadmium; Gene Expression Regulation, Plant; Hydrogen Peroxide; Microscopy, Confocal; Nitric Oxide; Peroxisomes; Plant Leaves; Real-Time Polymerase Chain Reaction
PubMed: 32692422
DOI: 10.1111/pce.13855 -
Aging Jul 2021The role of peroxisome proliferator activated receptor-γ (PPAR-γ) in neuronal apoptosis remains unclear. We aim to investigate the role of PPAR-γ in glucagon-like...
BACKGROUNDS AND AIMS
The role of peroxisome proliferator activated receptor-γ (PPAR-γ) in neuronal apoptosis remains unclear. We aim to investigate the role of PPAR-γ in glucagon-like peptide-1 (GLP-1) alleviated neuronal apoptosis induced by carboxymethyl-lysine (CML).
MATERIALS AND METHODS
, PC12 cells were treated by CML/GLP-1. Moreover. the function of PPAR-γ was blocked by GW9662. , streptozotocin (STZ) was used to induce diabetic rats with neuronal apoptosis. The cognitive function of rats was observed by Morris water maze. Apoptosis was detected by TUNEL assay. Bcl2, Bax, PPAR-γ and receptor of GLP-1 (GLP-1R) were measured by western blotting or immunofluorescence.
RESULTS
experiment, CML triggered apoptosis, down-regulated GLP-1R and PPAR-γ. Moreover, GLP-1 not only alleviated the apoptosis, but also increased levels of PPAR-γ. GW9662 abolished the neuroprotective effect of GLP-1 on PC12 cells from apoptosis. Furthermore, GLP-1R promoter sequences were detected in the PPAR-γ antibody pulled mixture. GPL-1 levels decreased, while CML levels increased in diabetic rats, compared with control rats. Additionally, we observed elevated bax, decreased bcl2, GLP-1R and PPAR-γ in diabetic rats.
CONCLUSIONS
GLP-1 could attenuate neuronal apoptosis induced by CML. Additionally, PPAR-γ involves in this process.
Topics: Alzheimer Disease; Animals; Apoptosis; Brain; Cognition; Diabetes Mellitus, Experimental; Glucagon-Like Peptide 1; Glycation End Products, Advanced; Lysine; Male; Maze Learning; Neurons; Neuroprotective Agents; PC12 Cells; PPAR gamma; Peroxisomes; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; bcl-2-Associated X Protein
PubMed: 34326274
DOI: 10.18632/aging.203351