Glyoxysomal β-oxidation of long-chain fatty acids: completeness of degradation

Kleiter, Anna Elisabeth; Gerhardt, Bernt

doi:10.1007/s004250050382

Cited by 11 publications

(19 citation statements)

References 25 publications

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“…Thus, in those species in which lox plays an important role in perturbing membrane function, UFA may be more readily available to lox. In species in which lox appears to have a minor role, it could be envisaged that after de-esterification, UFAs are actively channeled by mechanisms such as membrane blebbing (Hudak and Thompson, 1997;Thompson et al, 1998) to other cellular compartments, like the glyoxysome, for efficient ␤-oxidation (Kleiter and Gerhardt, 1998) and thus are unable to partake in lox-mediated reactions. Thus, based on the classification system of ethylene sensitivity/insensitivity and lox mediated or non-lox mediated, A. peruviana represents a distinct pattern of floral senescence that is both ethylene and lox independent.…”

Section: Discussionmentioning

confidence: 99%

Characterization of a Novel Lipoxygenase-Independent Senescence Mechanism in Alstroemeria peruviana Floral Tissue

Leverentz¹,

Wagstaff

Rogers

et al. 2002

Plant Physiology

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The role of lipoxygenase (lox) in senescence of Alstroemeria peruviana flowers was investigated using a combination of in vitro assays and chemical profiling of the lipid oxidation products generated. Phospholipids and galactolipids were extensively degraded during senescence in both sepals and petals and the ratio of saturated/unsaturated fatty acids increased. Lox protein levels and enzymatic activity declined markedly after flower opening. Stereochemical analysis of lox products showed that 13-lox was the major activity present in both floral tissues and high levels of 13-keto fatty acids were also synthesized. Lipid hydroperoxides accumulated in sepals, but not in petals, and sepals also had a higher chlorophyll to carotenoid ratio that favors photooxidation of lipids. Loss of membrane semipermeability was coincident for both tissue types and was chronologically separated from lox activity that had declined by over 80% at the onset of electrolyte leakage. Thus, loss of membrane function was not related to lox activity or accumulation of lipid hydroperoxides per se and differs in these respects from other ethylene-insensitive floral tissues representing a novel pattern of flower senescence.

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Section: Discussionmentioning

confidence: 99%

Characterization of a Novel Lipoxygenase-Independent Senescence Mechanism in Alstroemeria peruviana Floral Tissue

Leverentz¹,

Wagstaff

Rogers

et al. 2002

Plant Physiology

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“…When oilseeds germinate, glyoxysomes, a specialized form of peroxisome, differentiate, with TAG degradation occurring concomitantly (for review, see Olsen and Harada, 1995;Olsen, 1998). Plant glyoxysomes have been shown to contain the enzymes necessary for the complete degradation of the fatty acids through the process of ␤ -oxidation (Kleiter and Gerhardt, 1998;Hayashi et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

“…During oilseed germination, ␤ -oxidation of fatty acids is known to occur in the glyoxysome (Kleiter and Gerhardt, 1998;Hayashi et al, 1999). Acetyl-CoA that is produced by the degradation of fatty acids is converted into succinate by the glyoxylate cycle.…”

Section: Introductionmentioning

confidence: 99%

Arabidopsis A BOUT DE SOUFFLE, Which Is Homologous with Mammalian Carnitine Acyl Carrier, Is Required for Postembryonic Growth in the Light

et al. 2002

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The degradation of storage compounds just after germination is essential to plant development, providing energy and molecules necessary for the building of a photosynthetic apparatus and allowing autotrophic growth. We identified à bout de souffle ( bou ), a new Arabidopsis mutation. Mutant plants stopped developing after germination and degraded storage lipids, but they did not proceed to autotrophic growth. Neither leaves nor roots developed in the mutant. However, externally added sugar or germination in the dark could bypass this developmental block and allowed mutant plants to develop. The mutated gene was cloned using the transposon Dissociation as a molecular tag. The gene coding sequence showed similarity to those of the mitochondrial carnitine acyl carriers (CACs) or CAC-like proteins. In animals and yeast, these transmembrane proteins are involved in the transport of lipid-derived molecules across mitochondrial membranes for energy and carbon supply. The data presented here suggest that BOU identifies a novel mitochondrial pathway that is necessary to seedling development in the light. The BOU pathway would be an alternative to the well-known glyoxylate pathway.

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“…Together these enzymes are capable of the complete degradation of both saturated and unsaturated long-chain fatty acylCoAs to acetyl-CoA (6). The process involves the repeated cleavage of acetate units from the thiol end of the fatty acid.…”

mentioning

confidence: 99%

Promoter Trapping of a Novel Medium-chain Acyl-CoA Oxidase, Which Is Induced Transcriptionally during Arabidopsis Seed Germination

Eastmond¹,

Hooks²,

Williams³

et al. 2000

Journal of Biological Chemistry

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The first step of peroxisomal fatty acid ␤-oxidation is catalyzed by a family of acyl-CoA oxidase isozymes with distinct fatty acyl-CoA chain-length specificities. Here we identify a new acyl-CoA oxidase gene from Arabidopsis (AtACX3) following the isolation of a promotertrapped mutant in which ␤-glucuronidase expression was initially detected in the root meristem. In acx3 mutant seedlings medium-chain acyl-CoA oxidase activity was reduced by 95%, whereas long-and short-chain activities were unchanged. Despite this reduction in activity lipid catabolism and seedling development were not perturbed. AtACX3 was cloned and expressed in Escherichia coli. The recombinant enzyme displayed mediumchain acyl-CoA substrate specificity. Analysis of ␤-glucuronidase activity in acx3 revealed that, in addition to constitutive expression in the root axis, AtACX3 is also up-regulated strongly in the hypocotyl and cotyledons of germinating seedlings. This suggests that ␤-oxidation is regulated predominantly at the level of transcription in germinating oilseeds. After the discovery of AtACX3, the Arabidopsis acyl-CoA oxidase gene family now comprises four isozymes with substrate specificities that encompass the full range of acyl-CoA chain lengths that exist in vivo.

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Glyoxysomal β-oxidation of long-chain fatty acids: completeness of degradation

Cited by 11 publications

References 25 publications

Characterization of a Novel Lipoxygenase-Independent Senescence Mechanism in Alstroemeria peruviana Floral Tissue

Characterization of a Novel Lipoxygenase-Independent Senescence Mechanism in Alstroemeria peruviana Floral Tissue

Arabidopsis A BOUT DE SOUFFLE, Which Is Homologous with Mammalian Carnitine Acyl Carrier, Is Required for Postembryonic Growth in the Light

Promoter Trapping of a Novel Medium-chain Acyl-CoA Oxidase, Which Is Induced Transcriptionally during Arabidopsis Seed Germination

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