Low temperature and aging‐promoted expression of PUMP in potato tuber mitochondria

Nantes, Iseli L.; Fagian, Márcia M.; Catisti, Rosana; Arruda, Paulo; Maia, Ivan de Godoy; Vercesi, Anı́bal E.

doi:10.1016/s0014-5793(99)01017-0

Cited by 57 publications

(41 citation statements)

References 25 publications

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“…3, B and D). Thus, either StUCP was involved in the LA-induced depolarization of potato mitochondria as previously suggested (8,10), but it had to be insensitive to nucleotides, or this uncoupling is UCP-independent and unspecific.…”

Section: Effect Of Nucleotides On Potato Mitochondria In Restingmentioning

confidence: 74%

“…Recently, the Arabidopsis thaliana AtUCP1 gene was expressed in Escherichia coli and the isolated protein reconstituted into liposomes (7). Like mammalian UCPs, the plant UCP 1 requires free fatty acids for its activity and is inhibited by purine nucleotides (GDP, ATP, GTP, or ADP) (7)(8)(9)(10). At the mitochondrial level, it has been proposed that ATP, GTP, or GDP were absolutely required to get a fully coupled state in potato tuber mitochondria oxidizing succinate (1,8).…”

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confidence: 99%

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Alteration of Plant Mitochondrial Proton Conductance by Free Fatty Acids

Cabassa¹,

Mesneau²,

Miroux³

et al. 2002

Journal of Biological Chemistry

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We characterized the uncoupling activity of the plant uncoupling protein from Solanum tuberosum (StUCP) using mitochondria from intact potato tubers or from yeast (Saccharomyces cerevisiae) expressing the StUCP gene. Compared with mitochondria from transfected yeast, StUCP is present at very low levels in intact potato mitochondrial membranes (at least thirty times lower) as shown by immunodetection with anti-UCP1 antibodies. Under conditions that ruled out undesirable effects of nucleotides and free fatty acids on uncoupling activity measurement in plant mitochondria, the linoleic acid-induced depolarization in potato mitochondria was insensitive to the nucleotides ATP, GTP, or GDP. In addition, sensitivity to linoleic acid was similar in potato and in control yeast mitochondria, suggesting that uncoupling occurring in potato mitochondria was because of a UCP-independent proton diffusion process. By contrast, yeast mitochondria expressing StUCP exhibited a higher sensitivity to free fatty acids than those from the control yeast and especially a marked proton conductance in the presence of low amounts of linoleic acid. However, this fatty acid-induced uncoupling was also insensitive to nucleotides. Altogether, these results suggest that uncoupling of oxidative phosphorylation and heat production cannot be the dominant feature of StUCP expressed in native potato tissues. However, it could play a role in preventing reactive oxygen species production as proposed for mammalian UCP2 and UCP3.The discovery in plants of a mitochondrial uncoupling protein resembling uncoupling proteins from mammals raised the possibility of a new uncoupling mechanism involving a transport pathway for backflow of protons into the matrix of plant mitochondria (1, 2). Indeed, a protein fraction containing a purine nucleotide-sensitive, free fatty acid-activated uncoupling activity, called PUMP, has been isolated from potato tuber mitochondria and characterized after reconstitution in proteoliposomes (1). In addition, various cDNAs coding for putative UCPs were identified in plants such as potato, Arabidopsis thaliana, and skunk cabbage (Symplocarpus foetidus), a thermogenic plant from the Aracea family (3-6). Recently, the Arabidopsis thaliana AtUCP1 gene was expressed in Escherichia coli and the isolated protein reconstituted into liposomes (7). Like mammalian UCPs, the plant UCP 1 requires free fatty acids for its activity and is inhibited by purine nucleotides (GDP, ATP, GTP, or ADP) (7-10). At the mitochondrial level, it has been proposed that ATP, GTP, or GDP were absolutely required to get a fully coupled state in potato tuber mitochondria oxidizing succinate (1, 8). Similarly, it has been suggested that the fatty acid-induced uncoupling in wheat mitochondria was sensitive to purine nucleotides (11).In this paper, we sought to characterize better the properties of plant UCP-like protein by comparing the fatty acid-dependent uncoupling capacity of either native UCP present in intact potato mitochondria or StUCP expressed at a high lev...

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Section: Effect Of Nucleotides On Potato Mitochondria In Restingmentioning

confidence: 74%

mentioning

confidence: 99%

Alteration of Plant Mitochondrial Proton Conductance by Free Fatty Acids

Cabassa¹,

Mesneau²,

Miroux³

et al. 2002

Journal of Biological Chemistry

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“…Like mammalian UCPs, plant UCP homologs can be regulated by cold, and like AOX, they are postulated to decrease ROS production (Laloi et al, 1997;Kowaltowski et al, 1998;Sluse and Jarmuszkiewicz, 2000). Figure 9B shows the expression of two maize ucp genes that were identified by their amino acid similarities to cold-inducible potato UCP (StUCP; Nantes et al, 1999) and cold-insensitive wheat UCP1a (TaUCP; Murayama and Handa, 2000). Interestingly, unlike wheat ucp, the maize TaUCP homolog could be upregulated by cold ( Figure 9B, gels at right).…”

Section: Analysis Of Oxidative Stress In Ncs Mutantsmentioning

confidence: 99%

Differential Expression of Alternative Oxidase Genes in Maize Mitochondrial Mutants

et al. 2002

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We have examined the expression of three alternative oxidase ( aox ) genes in two types of maize mitochondrial mutants. Nonchromosomal stripe (NCS) mutants carry mitochondrial DNA deletions that affect subunits of respiratory complexes and show constitutively defective growth. Cytoplasmic male-sterile (CMS) mutants have mitochondrial DNA rearrangements, but they are impaired for mitochondrial function only during anther development. In contrast to normal plants, which have very low levels of AOX, NCS mutants exhibit high expression of aox genes in all nonphotosynthetic tissues tested. The expression pattern is specific for each type of mitochondrial lesion: the NADH dehydrogenase-defective NCS2 mutant has high expression of aox2 , whereas the cytochrome oxidase-defective NCS6 mutant predominantly expresses aox3 . Similarly, aox2 and aox3 can be induced differentially in normal maize seedlings by specific inhibitors of these two respiratory complexes. Translation-defective NCS4 plants show induction of both aox2 and aox3 . AOX2 and AOX3 proteins differ in their ability to be regulated by reversible dimerization. CMS mutants show relatively high levels of aox2 mRNAs in young tassels but none in ear shoots. Significant expression of aox1 is detected only in NCS and CMS tassels. The induction pattern of maize aox genes could serve as a selective marker for diverse mitochondrial defects.

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“…Potato mitochondria were isolated as described previously (5,8,9) in medium containing 250 mM sucrose, 10 mM HEPES, pH 7.2, and 0.3 mM EGTA. The protein concentration was 30-40 mg/ml, as determined by the biuret method.…”

Section: Isolation Of Mitochondria and Protein Determinationmentioning

confidence: 99%

“…Both functions are beneficial for plant growth and development. Thus, fully activated thermogenesis could facilitate plant growth at low temperature, e.g., in roots, tubers (9), or during seed germination. StUCP may also play specific roles during P. Jeek et al plant senescence and could contribute to processes that maintain the seed dormancy.…”

Section: Introductionmentioning

confidence: 99%

Important amino acid residues of potato plant uncoupling protein (StUCP)

Ježek

Costa

Vercesi

2000

Braz J Med Biol Res

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Chemical modifications were used to identify some of the functionally important amino acid residues of the potato plant uncoupling protein (StUCP). The proton-dependent swelling of potato mitochondria in K + -acetate in the presence of linoleic acid and valinomycin was inhibited by mersalyl (K i = 5 µM) and other hydrophilic SH reagents such as Thiolyte MB, iodoacetate and 5,5'-dithio-bis-(2-nitrobenzoate), but not by hydrophobic N-ethylmaleimide. This pattern of inhibition by SH reagents was similar to that of brown adipose tissue uncoupling protein (UCP1). As with UCP1, the arginine reagent 2,3-butadione, but not N-ethylmaleimide or other hydrophobic SH reagents, prevented the inhibition of StUCP-mediated transport by ATP in isolated potato mitochondria or with reconstituted StUCP. The results indicate that the most reactive amino acid residues in UCP1 and StUCP are similar, with the exception of N-ethylmaleimide-reactive cysteines in the purine nucleotide-binding site. Correspondence

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Low temperature and aging‐promoted expression of PUMP in potato tuber mitochondria

Cited by 57 publications

References 25 publications

Alteration of Plant Mitochondrial Proton Conductance by Free Fatty Acids

Alteration of Plant Mitochondrial Proton Conductance by Free Fatty Acids

Differential Expression of Alternative Oxidase Genes in Maize Mitochondrial Mutants

Important amino acid residues of potato plant uncoupling protein (StUCP)

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