Localization of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase in <i>Gracilaria secundata </i>(Rhodophyta) and its Role as a Nitrogen Storage Pool

Ekman, P.; Lignell, Åke; Pedersén, Marianne

doi:10.1515/botm.1989.32.6.527

Cited by 26 publications

(14 citation statements)

References 32 publications

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“…Thus, PBP could act as a N reserve in the context of a more general response of chloroplast proteins to N limitation. In agreement with this hypothesis, the selective response of the enzyme nbulose-1,5-biphosphate carboxylase/oxygenase (Rubisco) to N availability has been shown in microalgae (Falkowski et al 1989, Geider et al 1994) and in red algae (Lapointe & Duke 1984, Ekman et al 1989, Garcia-Sanchez et al 1993, where both Rubisco subunits are chloroplast-encoded proteins (Valentin & Zetsche 1989). This attractive hypothesis, proposed by Falkowski et al (1989), merits closer examination, and further investigation is need to elucidate the existence of such a mechanism in red algae.…”

Section: Differential Protein Synthesismentioning

confidence: 81%

Nitrogen assimilation following NH4+ pulses in the red alga Gracilariopsis lemaneiformis:effect on C metabolism

Jj¹,

Kt²,

Fx³

1995

Mar. Ecol. Prog. Ser.

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Nitrogen assimilation following NH4+ pulses in the red alga Gracilariopsis lemaneiformis: effect on C metabolism Juan J. V e r g a r a l , Kimon T. ~i r d~, F. X. ~i e l l~ ABSTRACT: The short-term effect of external NH,' availability on N assimilation, as well as on C metabolism, has been studied in the red alga Gracilariopsis lemaneiformis. This agarophyte seaweed showed a high capacity to take up external NH,' and to channel it toward proteins. As in a previous study in Corallina elongata, it appears that N limitation redirected the flow of internal N toward nonpigmented proteins, whereas phycobiliprotein synthesis was preferentially stimulated with respect to other proteins in response to external NH,+ pulses. A possible mechanism by which chloroplastic protein synthesis is limited by external N availability more than cytosolic proteins could be involved. In relation to C metabolism, insoluble and soluble carbohydrates were mobilized in response to NH,+ assimilation at a non-saturating irradiance for photosynthesls of 80 pm01 m-2 S-'. The main change in C metabolism was not seen for total C. The principal effect was the flow of C among different compounds, from carbohydrates to organic N compounds (amino acids and prote~ns) during transient NH, + assimilation.

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Section: Differential Protein Synthesismentioning

confidence: 81%

Nitrogen assimilation following NH4+ pulses in the red alga Gracilariopsis lemaneiformis:effect on C metabolism

Jj¹,

Kt²,

Fx³

1995

Mar. Ecol. Prog. Ser.

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“…However, these observations are based on studies with crude enzyme extracts and no detailed studies on puri®ed starch synthase preparations from red algae are available. Here we present the results of an investigation on starch synthase activity in the red alga Gracilaria tenuistipitata which, under certain growth conditions, can accumulate starch granules accounting for over 80% of the cell volume (Ekman et al 1989). We have found that UDPGlc is a considerably more eective glucosyl donor for starch synthase activity than ADPGlc in crude algal extracts.…”

Section: Introductionmentioning

confidence: 89%

Purification and characterisation of a novel starch synthase selective for uridine 5′-diphosphate glucose from the red alga Gracilaria tenuistipitata

Nyvall

Pelloux²,

Davies³

et al. 1999

Planta

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Red algae (Rhodophyceae) are photosynthetic eukaryotes that accumulate starch granules in the cytosol. Starch synthase activity in crude extracts of Gracilaria tenuistipitata Chang et Xia was almost 9-fold higher with UDP[U-14C]glucose than with ADP[U-14C]glucose. The activity with UDP[U-14C]glucose was sensitive to proteolytic and oxidative inhibition during extraction whilst the activity with ADP[U-14C]glucose appeared unaffected. This indicates the presence of separate starch synthases with different substrate specificities in G. tenuistipitata. The UDPglucose: starch synthase was purified and characterised. The enzyme appears to be a homotetramer with a native M(r) of 580 kDa and displays kinetic properties similar to other alpha-glucan synthases such as stimulation by citrate, product (UDP) inhibition and broad primer specificity. We propose that this enzyme is involved in cytosolic starch synthesis in red algae and thus is the first starch synthase described that utilises UDPglucose in vivo. The biochemical implications of the different compartmentalisation of starch synthesis in red algae and green algae/plants are also discussed.

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“…an optimisation of N sources during submersion (Thomas et al 1987a). Alternatively, N storage may occur as N compounds such as amino acids, proteins, chlorophyll and accessory pigments (Gagné et al 1982, Ekman et al 1989, Fredriksen & Rueness 1989, Naldi & Wheeler 1999) rather than as soluble vacuolar/cytoplasmic NO 3 -. The ability of macroalgae to store N as a variety of compounds suggests that total N may be a better indicator of N status.…”

Section: N Status Of Intertidal Algaementioning

confidence: 99%

Nitrogen ecophysiology of intertidal seaweeds from New Zealand: N uptake, storage and utilisation in relation to shore position and season

Phillips¹,

Hurd²

2003

Mar. Ecol. Prog. Ser.

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Localization of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase in Gracilaria secundata (Rhodophyta) and its Role as a Nitrogen Storage Pool

Cited by 26 publications

References 32 publications

Nitrogen assimilation following NH4+ pulses in the red alga Gracilariopsis lemaneiformis:effect on C metabolism

Nitrogen assimilation following NH4+ pulses in the red alga Gracilariopsis lemaneiformis:effect on C metabolism

Purification and characterisation of a novel starch synthase selective for uridine 5′-diphosphate glucose from the red alga Gracilaria tenuistipitata

Nitrogen ecophysiology of intertidal seaweeds from New Zealand: N uptake, storage and utilisation in relation to shore position and season

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