Purification and Characterization of Δ1-Pyrroline-5-Carboxylate Reductase Isoenzymes, Indicating Differential Distribution in Spinach (Spinacia oleracea L.) Leaves

Murahama, Minoru; Yoshida, Takayuki; Hayashi, Fumio; Ichino, Tsukasa; Sanada, Yukika; Wada, Keishiro

doi:10.1093/pcp/pce093

Cited by 37 publications

(47 citation statements)

References 47 publications

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“…To date, a broad range of oligomeric states of P5CR has been reported, extending from 125 kDa (suggesting tetramer) for yeast P5CR 37 to 200-340 kDa (octamer-dodecamer) observed for P5CRs purified from Clostridium sticklandii, Raltus norvegicus, Homo sapiens, Escherichia coli, and Spinacia oleracea. 7,10,[38][39][40] As shown by the crystal structures, these enzymes can exist as a dimer or as multimers of dimers. In Sp-P5CR, five dimers are arranged into a decamer resembling an hourglass-shaped barrel ( Figure 4).…”

Section: Dimer Interfacementioning

confidence: 99%

Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

Nocek¹,

Chang²,

Li³

et al. 2005

Journal of Molecular Biology

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L-Proline is an amino acid that plays an important role in proteins uniquely contributing to protein folding, structure, and stability, and this amino acid serves as a sequence-recognition motif. Proline biosynthesis can occur via two pathways, one from glutamate and the other from arginine. In both pathways, the last step of biosynthesis, the conversion of Δ 1 -pyrroline-5-carboxylate (P5C) to Lproline, is catalyzed by Δ 1 -pyrroline-5-carboxylate reductase (P5CR) using NAD(P)H as a cofactor. We have determined the first crystal structure of P5CR from two human pathogens, Neisseria meningitides and Streptococcus pyogenes, at 2.0Å and 2.15Å resolution, respectively. The catalytic unit of P5CR is a dimer composed of two domains, but the biological unit seems to be speciesspecific. The N-terminal domain of P5CR is an α/β/α sandwich, a Rossmann fold. The C-terminal dimerization domain is rich in α-helices and shows domain swapping. Comparison of the native structure of P5CR to structures complexed with L-proline and NADP + in two quite different primary sequence backgrounds provides unique information about key functional features: the active site and the catalytic mechanism. The inhibitory L-proline has been observed in the crystal structure.

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Section: Dimer Interfacementioning

confidence: 99%

Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

Nocek¹,

Chang²,

Li³

et al. 2005

Journal of Molecular Biology

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“…P5CR-1 and P5CR-2 had similar K m values for NADPH (9 and 19 µM, respectively) and P5C (0.122 and 0.162 mM). Both isoenzymes had strong preference for NADPH rather than NADH as the electron donor and also showed inhibition by ATP and Mg 2+ (Murahama et al, 2001). The preference for NADPH is likely to be significant in linking proline metabolism to the pentose phosphate pathway (see section IV.-A.…”

Section: Sro5 At5g62520mentioning

confidence: 96%

“…Similar to P5CS, the Arabidopsis P5CR is actually less studied at the protein level than the enzyme from other plants. Two isoenzymes of Spinacea oleracea (spinach) leaf P5CR, P5CR-1 and P5CR-2, were found to be differentially distributed with P5CR-2, but not P5CR-1 isolated from intact chloroplasts (Murahama et al, 2001). P5CR-1 and P5CR-2 had similar K m values for NADPH (9 and 19 µM, respectively) and P5C (0.122 and 0.162 mM).…”

Section: Sro5 At5g62520mentioning

confidence: 99%

Proline Metabolism and Its Implications for Plant-Environment Interaction

Verslues

Sharma

2010

The Arabidopsis Book

475

347

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Proline has long been known to accumulate in plants experiencing water limitation and this has driven studies of proline as a beneficial solute allowing plants to increase cellular osmolarity during water limitation. Proline metabolism also has roles in redox buffering and energy transfer and is involved in plant pathogen interaction and programmed cell death. Some of these unique roles of proline depend on the properties of proline itself, whereas others depend on the "proline cycle" of coordinated proline synthesis in the chloroplast and cytoplasm with proline catabolism in the mitochondria. The regulatory mechanisms controlling proline metabolism, intercellular and intracellular transport and connections of proline to other metabolic pathways are all important to the in vivo functions of proline metabolism. Connections of proline metabolism to the oxidative pentose phosphate pathway and glutamate-glutamine metabolism are of particular interest. The N-acetyl glutamate pathway can also produce ornithine and, potentially, proline but its role and activity are unclear. Use of model systems such as Arabidopsis thaliana to better understand both these long studied and newly emerging functions of proline can help in the design of nextgeneration experiments testing whether proline metabolism is a promising metabolic engineering target for improving stress resistance of economically important plants.

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“…The answer to this question is difficult to predict, because it is not yet clear whether Pro accumulates only in the cytoplasm or if it can also do so in the plastid stroma. The final step of Pro synthesis is catalyzed by D 1-pyrroline-5-carboxylate reductase (P5CR) and P5CR isoforms have been localized to both the cytoplasm and the plastid in tobacco (Nicotiana tabacum) and spinach (Spinacia oleracea; Szoke et al, 1992;Murahama et al, 2001). Identifying the subcellular localization of this enzyme and other Pro biosynthetic enzymes should help determine if Pro accumulation in the cytoplasm could help maintain some level of osmotic balance across the plastid envelope in the absence of MSL2 and MSL3.…”

Section: Future Investigation Into Plastid Osmoregulation and Osmosenmentioning

confidence: 99%

Plastid Osmotic Stress Activates Cellular Stress Responses in Arabidopsis

et al. 2014

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Little is known about cytoplasmic osmoregulatory mechanisms in plants, and even less is understood about how the osmotic properties of the cytoplasm and organelles are coordinately regulated. We have previously shown that Arabidopsis (Arabidopsis thaliana) plants lacking functional versions of the plastid-localized mechanosensitive ion channels Mechanosensitive Channel of Small Conductance-Like2 (MSL2) and MSL3 contain leaf epidermal plastids under hypoosmotic stress, even during normal growth and development. Here, we use the msl2 msl3 mutant as a model to investigate the cellular response to constitutive plastid osmotic stress. Under unstressed conditions, msl2 msl3 seedlings exhibited several hallmarks of drought or environmental osmotic stress, including solute accumulation, elevated levels of the compatible osmolyte proline (Pro), and accumulation of the stress hormone abscisic acid (ABA). Furthermore, msl2 msl3 mutants expressed Pro and ABA metabolism genes in a pattern normally seen under drought or osmotic stress. Pro accumulation in the msl2 msl3 mutant was suppressed by conditions that reduce plastid osmotic stress or inhibition of ABA biosynthesis. Finally, treatment of unstressed msl2 msl3 plants with exogenous ABA elicited a much greater Pro accumulation response than in the wild type, similar to that observed in plants under drought or osmotic stress. These results suggest that osmotic imbalance across the plastid envelope can elicit a response similar to that elicited by osmotic imbalance across the plasma membrane and provide evidence for the integration of the osmotic state of an organelle into that of the cell in which it resides.

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Purification and Characterization of Δ1-Pyrroline-5-Carboxylate Reductase Isoenzymes, Indicating Differential Distribution in Spinach (Spinacia oleracea L.) Leaves

Cited by 37 publications

References 47 publications

Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

Proline Metabolism and Its Implications for Plant-Environment Interaction

Plastid Osmotic Stress Activates Cellular Stress Responses in Arabidopsis

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