Plitidepsin to treat multiple myeloma.

While remaining relatively rare, multiple myeloma (MM) accounts for approximately 10% of all hematological malignancies, being an insidious disease with an overall 5-year survival rate of 52%. In addition to other associated complications, myeloma bone disease further aggravates MM patients, the majority of whom suffer from lytic lesions, leading to pain, fractures, mobility issues and neurological deficits. Patients not responding or becoming resistant to prior therapies have now a novel therapeutic tool with an unprecedent mode of action, differing from those currently in use. The anticancer effects of the marine-derived antitumor agent plitidepsin primarily rely on the interaction with elongation factor 1-α 2 (eEF1A2), known to be overexpressed in breast cancer and MM cells, targeting the noncanonical role of the protein and leading to a proapoptotic response. Following the drug's approval from Australian regulatory authorities, eligible patients will have access to a new first-in-class drug to treat MM, expanding the current anti-MM portfolio. Plitidepsin (Aplidin; PharmaMar) was approved in combination with the corticosteroid agent dexamethasone, to treat MM patients who failed or became resistant to other therapies, covering the third- and fourth-line treatment setting.

Avaliação anatômica das artérias radiais e ulnares em adultos submetidos à intervenção coronariana percutânea / Anatomical evaluation of radial and ulnar arteries in adults undergoing percutaneous coronary intervention

INTRODUÇÃO: A artéria radial tornou-se, recentemente, uma alternativa de acesso vascular muito popular nos procedimentos percutâneos coronarianos. Contudo, apesar do uso de cateteres com diâmetro maior ser fator de risco para oclusão da artéria radial, a mensuração do tamanho da mesma não é realizada rotineiramente. MÉTODOS: Com uso da ultrassonagrafia, realizou-se, prospectivamente, a mensuração do diâmetro das artérias radiais e ulnares de 317 pacientes submetidos à angiocoronariografia e/ou intervenção coronariana percutânea em serviços de referência em cardiologia no sul, sudeste e centro oeste do País. Além disso foi verificado as características demográficas e clínicas desta população. Os dados foram tabulados e analisados no programa Statistical Package for the Social Sciences (SPSS). Version 18.0, conforme frequência, média e desvio padrão. RESULTADOS: O diâmetro interno médio das artérias radial e ulnar direitas foi de 2,836±0,7mm e 2,155±0,58mm, respectivamente. Os resultados das artérias contralaterais foram similares (radial 2,53±0,63mm, ulnar 2,15±0,55mm). 20,5% dos pacientes apresentaram diâmetro da artéria radial direita inferiores à 2,3mm e 38,5% menor que 2,5mm, equivalente aos diâmetros dos introdutores Terumo® GSS 5Fr e 6Fr, respectivamente. A circunferência média do punho direito foi de 17,273±1,39cm, também semelhante ao punho esquerdo (17,33±1,39cm). A média de idade foi de 60±10,89 anos. O peso médio encontrou-se na faixa de 76,34±15 kg e a altura 164,1±8,9cm. Houve predomínio do sexo masculino (61%), a comorbidade mais prevalente foi a hipertensão (73%) e 70% dos pacientes apresentaram-se como síndrome coronariana aguda. CONCLUSÃO: Em aproximadamente 40% dos pacientes da amostra foi verificado um diâmetro inferior à 2,5mm da artéria radial direita, sendo este um valor menor ao do introdutor utilizado para sua abordagem nos casos de intervenção coronariana percutânea. (AU)

Evaluation of the neuroprotective and antidiabetic potential of phenol-rich extracts from virgin olive oils by in vitro assays.

In this work, phenol-rich extracts from 'Cornicabra' and 'Picual' virgin-olive oils (EVOOs) were examined, for the first time, to establish their capacity to inhibit key enzymes involved in Alzheimer's disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and 5-lipoxygenase (LOX)), major depressive disorder (MDD) and Parkinson's disease (PD) (monoamine oxidases: hMAO-A and hMAO-B respectively), and diabetes mellitus (DM) (α-glucosidase and α-amylase). 'Cornicabra' displayed the best inhibitory activity against all enzymes, when compared to 'Picual': BuChE (IC50 = 156 ±â€¯4 and 308 ±â€¯33 mg mL-1), LOX (IC50 = 26 ±â€¯0.5 and 37 ±â€¯3 mg mL-1), hMAO-A (IC50 = 20 ±â€¯2 and 37 ±â€¯0.2 mg mL-1), hMAO-B (IC50 = 131 ±â€¯7 and 215 ±â€¯13 mg mL-1) and α-glucosidase (IC50 = 154 ±â€¯17 and 251 ±â€¯31 mg mL-1), respectively. The behaviour observed can be associated with the higher content of secoiridoids, lignans and phenolic acids in 'Cornicabra' EVOO.

HPLC-DAD-ESI/MS(n) profiling of phenolic compounds from Lathyrus cicera L. seeds.

Lathyrus cicera L. seeds are of interest for food and feed purposes. Despite the recognized antioxidant activity of the seeds, arising from the phenolic fraction, their phenolic compounds have not been studied in depth yet. Therefore, to determine the phenolics profile of these seeds, a target analysis was performed using high-performance liquid chromatography coupled to photodiode-array detection and electrospray ionization/ion trap mass spectrometry (HPLC-DAD-ESI/MS(n)). Thirty-seven glycosylated flavonoids were identified for the first time in the seeds of this species and, according to their MS fragmentation, clustered in flavonol-3-O-di-/tri-glycosides-7-O-rhamnosides and other flavonol-glycosides, and flavonol-3-O-(cinnamoyl)glycoside-7-O-rhamnosides, flavonol-3-O-(dihydrophaseoyl, cinnamoyl)glycoside-7-O-rhamnosides and flavonol-3-O-(malonyl)glycoside-7-O-rhamnosides. Glycosides of kaempferol were the main flavonoids found (10 non-acylated and 21 acylated), followed by those of quercetin (3) and those of isorhamnetin, apigenin and luteolin (1). The most abundant flavonols were identified as kaempferol-3-O-(2-hexosyl)hexoside-7-O-rhamnosides. The methodology used allowed to increase the knowledge on a relevant phytochemical class of seeds from L. cicera.

The use of flavonoids in central nervous system disorders.

Neurodegenerative, neurological and psychiatric diseases are a group of pathologies with huge social and economic impacts. Since brain disorders continue to be pathological conditions for which corrective surgery cannot be widely used, treatments are based on drugs that only alleviate the symptoms. Despite all efforts in finding more efficient therapeutic agents, the requirement for neuroprotective drugs able to cross the blood-brain barrier (BBB) has been a hard challenge to overcome. Flavonoids are known by their antioxidant activities thus preventing oxidative stress, which is believe to be one of the causes of disorders affecting the central nervous system. Moreover, they can also modulate both enzymes and receptors activities, being regarded as multi-target botanical therapeutics or drugs. This review will give emphasis to the benefits of flavonoids found in the diet in the treatment of Alzheimer's disease, Parkinson's disease, epilepsy, depression, and schizophrenia. The antioxidant effect of several flavonoids, as well as their effects not related with antioxidant activity, in the above mentioned diseases will be reviewed. Aspects concerning structure-activity relationships, but also the bioavailability of these compounds in the brain will be referred.

Alzheimer's disease and antioxidant therapy: how long how far?

Alzheimer's disease (AD) has become a health problem to societies worldwide affecting millions of people. AD normally ensues in middle and late life but its specific cause remains unknown. Besides amyloid-ß deposition and hyperphosphorylated tau protein, increased production of reactive species (RS) has also been described to be a hallmark in early steps of this disorder. Antioxidant therapy has received considerable attention over the last years as a promising approach to delay or slow the neurodegeneration progression in AD either by boosting the pool of endogenous antioxidants (e.g.vitamins, coenzyme Q10 or melatonin) or by the intake of dietary antioxidants, such as phenolic compounds of flavonoid or non-flavonoid type. However, the majority of antioxidants studied so far have limited success in clinical trials, a fact that could be related to their poor distribution and with the inherent difficulties to cross the blood brain barrier and attain the target sites. Despite the evidence that different classes of antioxidants are neuroprotectants in vitro, the clinical data is not consistent. Alzheimer's disease and antioxidant therapy is still an open question: the research is far from the end but the success may not be so time-consuming if the data obtained so far are gathered and rationally analyzed either by checking new targets or by the obtention of new and effective compounds, for instance by the rational modification of the previous ones.

Novel TMPRSS3 variants in Pakistani families with autosomal recessive non-syndromic hearing impairment.

Mutations in the TMPRSS3 gene are known to cause autosomal recessive non-syndromic hearing impairment (ARNSHI). After undergoing a genome scan, 10 consanguineous Pakistani families with ARNSHI were found to have significant or suggestive evidence of linkage to the TMPRSS3 region. In order to elucidate if the TMPRSS3 gene is responsible for ARNSHI in these families, the gene was sequenced using DNA samples from these families. Six TMPRSS3 variants were found to cosegregate in 10 families. None of these variants were detected in 500 control chromosomes. Four novel variants, three of which are missense [c.310G>A (p.Glu104Lys), c.767C>T (p.Ala256Val) and c.1273T>C (p.Cys425Arg)] and one nonsense [c.310G>T (p.Glu104Stop)], were identified. The pathogenicity of novel missense variants was investigated through bioinformatics analyses. Additionally, the previously reported deletion c.208delC (p.His70ThrfsX19) was identified in one family and the known mutation c.1219T>C (p.Cys407Arg) was found in five families, which makes c.1219T>C (p.Cys407Arg) as the most common TMPRSS3 mutation within the Pakistani population. Identification of these novel variants lends support to the importance of elements within the low-density lipoprotein receptor A (LDLRA) and serine protease domains in structural stability, ligand binding and proteolytic activity for proper TMPRSS3 function within the inner ear.

Water extracts of Brassica oleracea var. costata potentiate paraquat toxicity to rat hepatocytes in vitro.

Tronchuda cabbage extracts have been proven to have antioxidant potential against various oxidative species in cell free systems, though its antioxidant potential in cellular models remained to be demonstrated. In the present study, we used primary cultures of rat hepatocytes for the cellular assay system and paraquat PQ exposure as a pro-oxidant model agent, to test whether tronchuda cabbage hydrolysed water extracts provide protective or aggravating effects towards PQ-induced oxidative stress and cell death. For this purpose cellular parameters related to oxidative stress were measured, namely the generation of superoxide anion, glutathione oxidation, lipid peroxidation, intracellular ATP levels, activation of nuclear factor-kappaB (NF-kappaB), activity of antioxidant enzymes, and cell death. The obtained results demonstrated that the studied hydrolysed water extracts of tronchuda cabbage, especially rich in kaempferol (84%) and other polyphenols, namely hydroxycinnamic acids and traces of quercetin, can potentiate the toxicity of PQ in primary cultures of rat hepatocytes. These results highlight that prospective antioxidant effects of plant extracts, observed in vitro, using non-cellular systems, are not always confirmed in cellular models, in which the concentrations required to scavenge pro-oxidant species may be highly detrimental to the cells.

Expression of fibroblast growth factor receptors during development and regression of the bovine corpus luteum.

There is evidence that fibroblast growth factors (FGFs) are involved in the regulation of growth and regression of the corpus luteum (CL). However, the expression pattern of most FGF receptors (FGFRs) during CL lifespan is still unknown. The objective of the present study was to determine the pattern of expression of 'B' and 'C' splice variants of FGFRs in the bovine CL. Bovine CL were collected from an abattoir and classed as corpora hemorrhagica (Stage I), developing (Stage II), developed (Stage III) or regressed (Stage IV) CL. Expression of FGFR mRNA was measured by semiquantitative reverse transcription-polymerase chain reaction and FGFR protein was localised by immunohistochemistry. Expression of mRNA encoding the 'B' and 'C' spliced forms of FGFR1 and FGFR2 was readily detectable in the bovine CL and was accompanied by protein localisation. FGFR1C and FGFR2C mRNA expression did not vary throughout CL lifespan, whereas FGFR1B was upregulated in the developed (Stage III) CL. FGFR3B, FGFR3C and FGFR4 expression was inconsistent in the bovine CL. The present data indicate that FGFR1 and FGFR2 splice variants are the main receptors for FGF action in the bovine CL.

Principal components of phenolics to characterize red Vinho Verde grapes: anthocyanins or non-coloured compounds?

Phenolic profile of 10 different varieties of red "Vinho Verde" grapes (Azal Tinto, Borraçal, Brancelho, Doçal, Espadeiro, Padeiro de Basto, Pedral, Rabo de ovelha, Verdelho and Vinhão), from Minho (Portugal) were studied. Nine Flavonols, four phenolic acids, three flavan-3-ols, one stilben and eight anthocyanins were determined. Malvidin-3-O-glucoside was the most abundant anthocyanin while the main non-coloured compound was much more heterogeneous: catechin, epicatechin, myricetin-3-O-glucoside, quercetin-3-O-glucoside or syringetin-3-O-glucoside. Anthocyanin contents ranged from 42 to 97%. Principal component analysis (PCA) was applied to analyse the date and study the relations between the samples and their phenolic profiles. Anthocyanin profile proved to be a good marker to characterize the varieties even considering different origin and harvest. "Vinhão" grapes showed anthocyanins levels until twenty four times higher than the rest of the samples, with 97% of these compounds.

Assessing the antioxidative properties and chemical composition of Linaria vulgaris infusion.

The ability of Linaria vulgaris (Scrophulariaceae) infusion to act as a scavenger of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, reactive oxygen species (superoxide radical, hydroxyl radical, hypochlorous acid (HOCl)) and nitric oxide was investigated. The obtained data indicate that the infusion has a good scavenging activity against superoxide radical and is a very potent nitric oxide and DPPH scavenger. In hydroxyl radical assay a pro-oxidant capacity was noticed, especially for concentrations higher than 31.25 microg mL(-1). No effect was found against HOCl. A phytochemical study of this extract was also performed. The HPLC/UV analysis allowed the identification and quantification of eight organic acids (oxalic, aconitic, citric, ketoglutaric, ascorbic, malic, shikimic and fumaric acids). The phenolic composition of the lyophilised infusion was also determined by HPLC/DAD and four compounds were quantified, but, despite its high content, only linarin was managed to be identified.

Further knowledge on barley (Hordeum vulgare L.) leaves O-glycosyl-C-glycosyl flavones by liquid chromatography-UV diode-array detection-electrospray ionisation mass spectrometry.

Thirty-seven flavonoids and a hydroxycynnamic acid have been characterized in barley leaves (Hordeum vulgare L.) by liquid chromatography-UV diode-array coupled to ion trap mass spectrometry with electrospray ionisation interface (negative mode). Their structures have been determined by the study of the ion mass fragmentation which characterizes C-glycosyl flavones and O-glycosyl-C-glycosyl flavones, and differentiates di-O-glycosyl flavones from O-diglycosyl-flavones. The majority of them are described for the first time in barley. Saponarin (isovitexin-7-O-glucoside), lutonarin (isoorientin-7-O-glucoside) and isoscoparin-7-O-glucoside derivatives constitute the major part of the detected compounds. Some acylated derivatives are also described, namely, 7-O-[6-acyl]-glucoside and -7-O-[6-acyl]-glc-4'-glucoside of isovitexin, isoorientin and isoscoparin.

Characterization of C-glycosyl flavones O-glycosylated by liquid chromatography-tandem mass spectrometry.

Fifty three O-glycosyl-C-glycosyl flavones with O-glycosylation on phenolic hydroxyl or on the C-glycosyl residue or combination of both forms have been studied by liquid chromatography-UV diode array detection-electrospray ionisation mass spectrometry ion trap in the negative mode. The study of the relative abundance of the main ions from the MS preferential fragmentation on -MS2 and/or -MS3 events allows the differentiation of the position of the O-glycosylation, either on phenolic hydroxyl or on the sugar moiety of C-glycosylation. In addition, it is possible to discriminate between O-glycosylation at 2'' and at 6'' positions. The occurrence of an abundant ion Y(0)(-) ([(M-H)-132/-146/-162](-), mono-O-pentosyl/rhamnosyl/hexosyl-C-glycosyl derivatives) after -MS2 fragmentation characterizes the O-glycosylation on phenolic hydroxyls. The preferential fragmentation leading to a relevant Z(1)(-) ([Y(1)-18](-)) fragment is characteristic of 2''-O-glycosyl-C-glycosyl derivatives. The 6''-O-glycosyl-C-glycosyl derivatives are characterized by (0,2)X(0)(-), which is generated by a global loss of the sugar moiety from the O-glycosylation at 6'' and the glycosidic fraction that involves the carbons 6''-3'' of the C-glycosyl residue ([(M-H)-162-120](-), in the case of 6''-O-hexosyl-C-hexosyl derivatives). Regarding the combined O-glycosylated compounds (both on phenolic hydroxyl and on sugar moiety at C-glycosylation), the main fragmentation on -MS2 events produces a Y(0)(-) characterizing the O-glycosylation on the phenolic hydroxyl, and the -MS3[(M-H)-->Y(0)](-) fragmentation of the O-glycosylation on the C-glycosyl residue.

Experimental design for extraction and quantification of phenolic compounds and organic acids in white "Vinho Verde" grapes.

An experimental design was applied for the optimization of extraction and clean-up processes of phenolic compounds and organic acids from white "Vinho Verde" grapes. The developed analytical method consisted in two steps: first a solid-liquid extraction of both phenolic compounds and organic acids and then a clean-up step using solid-phase extraction (SPE). Afterwards, phenolic compounds and organic acids were determined by high-performance liquid chromatography (HPLC) coupled to a diode array detector (DAD) and HPLC-UV, respectively. Plackett-Burman design was carried out to select the significant experimental parameters affecting both the extraction and the clean-up steps. The identified and quantified phenolic compounds were: quercetin-3-O-glucoside, quercetin-3-O-rutinoside, kaempferol-3-O-rutinoside, isorhamnetin-3-O-glucoside, quercetin, kaempferol and epicatechin. The determined organic acids were oxalic, citric, tartaric, malic, shikimic and fumaric acids. The obtained results showed that the most important variables were the temperature (40 degrees C) and the solvent (acid water at pH 2 with 5% methanol) for the extraction step and the type of sorbent (C18 non end-capped) for the clean-up step.

Solid-phase extraction versus matrix solid-phase dispersion: Application to white grapes.

The use of matrix solid-phase dispersion (MSPD) was tested to, separately, extract phenolic compounds and organic acids from white grapes. This method was compared with a more conventional analytical method previously developed that combines solid liquid extraction (SL) to simultaneously extract phenolic compounds and organic acids followed by a solid-phase extraction (SPE) to separate the two types of compounds. Although the results were qualitatively similar for both techniques, the levels of extracted compounds were in general quite lower on using MSPD, especially for organic acids. Therefore, SL-SPE method was preferred to analyse white "Vinho Verde" grapes. Twenty samples of 10 different varieties (Alvarinho, Avesso, Asal-Branco, Batoca, Douradinha, Esganoso de Castelo Paiva, Loureiro, Pedernã, Rabigato and Trajadura) from four different locations in Minho (Portugal) were analysed in order to study the effects of variety and origin on the profile of the above mentioned compounds. Principal component analysis (PCA) was applied separately to establish the main sources of variability present in the data sets for phenolic compounds, organic acids and for the global data. PCA of phenolic compounds accounted for the highest variability (77.9%) with two PCs, enabling characterization of the varieties of samples according to their higher content in flavonol derivatives or epicatechin. Additionally, a strong effect of sample origin was observed. Stepwise linear discriminant analysis (SLDA) was used for differentiation of grapes according to the origin and variety, resulting in a correct classification of 100 and 70%, respectively.

Mitochondrial damages and the regulation of insulin secretion.

Pancreatic beta-cells are able to respond to nutrients, principally glucose, as the primary stimulus for insulin exocytosis. This unique feature requires translation of metabolic substrates into intracellular messengers recognized by the exocytotic machinery. Central to this signal transduction mechanism, mitochondria integrate and generate metabolic signals, thereby coupling glucose recognition with insulin secretion. In response to a glucose rise, nucleotides and metabolites are generated by mitochondria and participate, together with cytosolic Ca2+, in the stimulation of insulin exocytosis. Mitochondrial defects, such as mutations and ROS (reactive oxygen species) production, might be associated with beta-cell failure in the course of diabetes. mtDNA (mitochondrial DNA) mutation A3243G is associated with MIDD (mitochondrial inherited diabetes and deafness). A common hypothesis to explain the link between the genotype and the phenotype is that the mutation might impair mitochondrial metabolism expressly required for beta-cell functions, although this assumption lacks direct demonstration. mtDNA-deficient cellular models are glucose-unresponsive and are defective in mitochondrial function. Recently, we used clonal cytosolic hybrid cells (namely cybrids) harbouring mitochondria derived from MIDD patients. Compared with control mtDNA from the same patient, the A3243G mutation markedly modified metabolic pathways. Moreover, cybrid cells carrying patient-derived mutant mtDNA exhibited deranged cell Ca2+ handling and elevated ROS under metabolic stress. In animal models, transgenic mice lacking expression of the mitochondrial genome specifically in beta-cells are diabetic and their islets are incable of releasing insulin in response to glucose. These various models demonstrate the fragility of nutrient-stimulated insulin secretion, caused primarily by defective mitochondrial function.

Diabetes-associated mitochondrial DNA mutation A3243G impairs cellular metabolic pathways necessary for beta cell function.

AIMS/HYPOTHESIS: Mitochondrial DNA (mtDNA) mutations cause several diseases, including mitochondrial inherited diabetes and deafness (MIDD), typically associated with the mtDNA A3243G point mutation on tRNALeu gene. The common hypothesis to explain the link between the genotype and the phenotype is that the mutation might impair mitochondrial metabolism expressly required for beta cell functions. However, this assumption has not yet been tested. METHODS: We used clonal osteosarcoma cytosolic hybrid cells (namely cybrids) harbouring mitochondria derived from MIDD patients and containing either exclusively wild-type or mutated (A3243G) mtDNA. According to the importance of mitochondrial metabolism in beta cells, we studied the impact of the mutation on key parameters by comparing stimulation of these cybrids by the main insulin secretagogue glucose and the mitochondrial substrate pyruvate. RESULTS: Compared with control mtDNA from the same patient, the A3243G mutation markedly modified metabolic pathways leading to a high glycolytic rate (2.8-fold increase), increased lactate production (2.5-fold), and reduced glucose oxidation (-83%). We also observed impaired NADH responses (-56%), negligible mitochondrial membrane potential, and reduced, only transient ATP generation. Moreover, cybrid cells carrying patient-derived mutant mtDNA exhibited deranged cell calcium handling with increased cytosolic loads (1.4-fold higher), and elevated reactive oxygen species (2.6-fold increase) under glucose deprivation. CONCLUSIONS/INTERPRETATION: The present study demonstrates that the mtDNA A3243G mutation impairs crucial metabolic events required for proper cell functions, such as coupling of glucose recognition to insulin secretion.

Hydroxyl radical and hypochlorous acid scavenging activity of small centaury (Centaurium erythraea) infusion. A comparative study with green tea (Camellia sinensis).

Small centaury (Centaurium erythraea Rafin.) is a herbal species with a long use in traditional medicine due to its digestive, stomachic, tonic, depurative, sedative and antipyretic properties. This species is reported to contain considerable amounts of polyphenolic compounds, namely xanthones and phenolic acids as the main constituents. Although the antiradicalar activity of some pure polyphenolic compounds is already known, it remains unclear how a complex mixture obtained from plant extracts functions against reactive oxygen species. Thus, the ability of small centaury infusion to act as a scavenger of the reactive oxygen species hydroxyl radical and hypochlorous acid was studied and compared with that of green tea (Camellia sinensis L.). Hydroxyl radical was generated in the presence of Fe3+-EDTA, ascorbate and H2O2 (Fenton system) and monitored by evaluating hydroxyl radical-induced deoxyribose degradation. The reactivity towards hypochlorous acid was determined by measuring the inhibition of hypochlorous acid-induced 5-thio-2-nitrobenzoic acid oxidation to 5,5'-dithiobis(2-nitrobenzoic acid). The obtained results demonstrate that small centaury infusion exhibits interesting antioxidant properties, expressed both by its capacity to effectively scavenge hydroxyl radical and hypochlorous acid, although with a lower activity against the second than that observed for green tea. Green tea exhibited a dual effect at the hydroxyl radical scavenging assay, stimulating deoxyribose degradation at lower dosages.

Functional reconstitution of Arabidopsis thaliana plant uncoupling mitochondrial protein (AtPUMP1) expressed in Escherichia coli.

The Arabidopsis thaliana uncoupling protein (UCP) gene was expressed in Escherichia coli and isolated protein reconstituted into liposomes. Linoleic acid-induced H+ fluxes were sensitive to purine nucleotide inhibition with an apparent K(i) (in mM) of 0.8 (GDP), 0.85 (ATP), 0.98 (GTP), and 1.41 (ADP); the inhibition was pH-dependent. Kinetics of AtPUMP1-mediated H+ fluxes were determined for lauric, myristic, palmitic, oleic, linoleic, and linolenic acids. Properties of recombinant AtPUMP1 indicate that it represents a plant counterpart of animal UCP2 or UCP3. This work brings the functional and genetic approaches together for the first time, providing strong support that AtPUMP1 is truly an UCP.