Isolation and characterization of peroxisomes from diatoms

Winkler, U.; Stabenau, H.

doi:10.1007/bf00202598

Cited by 33 publications

(38 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar to green algae, previous studies indicated that glycolate oxidation in diatoms is catalyzed by a glycolate dehydrogenase localized in peroxisomes (Winkler and Stabenau 1995). However, our and previously reported BlastP analyses identified the two GOX-like proteins, one with a peroxisomal targeting PTS1 and the other (XP_002178591 of Phaeodactylum) possibly targeted to mitochondria (Kroth et al 2008).…”

Section: Glycolate Oxidasementioning

confidence: 65%

Evolution of enzymes involved in the photorespiratory 2-phosphoglycolate cycle from cyanobacteria via algae toward plants

2011

View full text Add to dashboard Cite

The photorespiratory pathway was shown to be essential for organisms performing oxygenic photosynthesis, cyanobacteria, algae, and plants, in the present day O(2)-containing atmosphere. The identification of a plant-like 2-phosphoglycolate cycle in cyanobacteria indicated that not only genes of oxygenic photosynthesis but also genes encoding photorespiratory enzymes were endosymbiotically conveyed from ancient cyanobacteria to eukaryotic oxygenic phototrophs. Here, we investigated the origin of the photorespiratory pathway in photosynthetic eukaryotes by phylogenetic analysis. We found that a mixture of photorespiratory enzymes of either cyanobacterial or α-proteobacterial origin is present in algae and higher plants. Three enzymes in eukaryotic phototrophs clustered closely with cyanobacterial homologs: glycolate oxidase, glycerate kinase, and hydroxypyruvate reductase. On the other hand, the mitochondrial enzymes of the photorespiratory cycle in algae and plants, glycine decarboxylase subunits and serine hydroxymethyltransferase, evolved from proteobacteria. Other than most genes for proteins of the photosynthetic machinery, nearly all enzymes involved in the 2-phosphogylcolate metabolism coexist in the genomes of cyanobacteria and heterotrophic bacteria.

show abstract

Section: Glycolate Oxidasementioning

confidence: 65%

Evolution of enzymes involved in the photorespiratory 2-phosphoglycolate cycle from cyanobacteria via algae toward plants

2011

View full text Add to dashboard Cite

show abstract

“…Enzymes in diatom peroxisomes include a glycolate dehydrogenase that also oxidises L-lactate and enzymes of the glyoxylate cycle (Winkler and Stabenau 1995). Mitochondria have a glycolate dehydrogenase that also oxidises D-lactate, and can convert the resulting glyoxylate to serine and CO 2 .…”

Section: Photorespiration In Diatomsmentioning

confidence: 99%

Carbon acquisition by diatoms

et al. 2007

View full text Add to dashboard Cite

Diatoms are responsible for up to 40% of primary productivity in the ocean, and complete genome sequences are available for two species. However, there are very significant gaps in our understanding of how diatoms take up and assimilate inorganic C. Diatom plastids originate from secondary endosymbiosis with a red alga and their Form ID Rubisco (ribulose-1,5-bisphosphate carboxylase-oxygenase) from horizontal gene transfer, which means that embryophyte paradigms can only give general guidance as to their C acquisition mechanisms. Although diatom Rubiscos have relatively high CO(2) affinity and CO(2)/O(2) selectivity, the low diffusion coefficient for CO(2) in water has the potential to restrict the rate of photosynthesis. Diatoms growing in their natural aquatic habitats operate inorganic C concentrating mechanisms (CCMs), which provide a steady-state CO(2) concentration around Rubisco higher than that in the medium. How these CCMs work is still a matter of debate. However, it is known that both CO(2) and HCO (3) (-) are taken up, and an obvious but as yet unproven possibility is that active transport of these species across the plasmalemma and/or the four-membrane plastid envelope is the basis of the CCM. In one marine diatom there is evidence of C(4)-like biochemistry which could act as, or be part of, a CCM. Alternative mechanisms which have not been eliminated include the production of CO(2) from HCO (3) (-) at low pH maintained by a H(+) pump, in a compartment close to that containing Rubisco.

show abstract

“…Photorespiration also provides energy to make amino acids for proteins associated with the diatom cell wall. Serine and glycine, enriched in proteins of the wall (Hecky et al 1973, Volcani 1981, Swift and Wheeler 1992), are synthesized via a pathway related to the classic glycolate pathway of photorespiration (Burris 1977, Winkler and Stabenau 1995). Their concentrations are regulated during the cell cycle, reaching maxima at the time of cell division and new valve deposition in T. weissflogii (Martin‐Jézéquel 1992).…”

Section: Energetics Of Silicificationmentioning

confidence: 99%

Silicon Metabolism in Diatoms: Implications for Growth

Martin‐Jézéquel

Hildebrand

Brzezinski

2000

Journal of Phycology

828

598

View full text Add to dashboard Cite

Diatoms are the world's largest contributors to biosilicification and are one of the predominant contributors to global carbon fixation. Silicon is a major limiting nutrient for diatom growth and hence is a controlling factor in primary productivity. Because our understanding of the cellular metabolism of silicon is limited, we are not fully knowledgeable about intracellular factors that may affect diatom productivity in the oceans. The goal of this review is to present an overview of silicon metabolism in diatoms and to identify areas for future research. Numerous studies have characterized parameters of silicic acid uptake by diatoms, and molecular characterization of transport has begun with the isolation of genes encoding the transporter proteins. Multiple types of silicic acid transporter gene have been identified in a single diatom species, and multiple types appear to be present in all diatom species. The controlled expression and perhaps localization of the transporters in the cell may be factors in the overall regulation of silicic acid uptake. Transport can also be regulated by the rate of silica incorporation into the cell wall, suggesting that an intracellular sensing and control mechanism couples transport with incorporation. Sizable intracellular pools of soluble silicon have been identified in diatoms, at levels well above saturation for silica solubility, yet the mechanism for maintenance of supersaturated levels has not been determined. The mechanism of intracellular transport of silicon is also unknown, but this must be an important part of the silicification process because of the close coupling between silica incorporation and uptake. Although detailed ultrastructural analyses of silica deposition have been reported, we know little about the molecular details of this process. However, proteins occluded within silica that promote silicification in vitro have recently been characterized, and the application of molecular techniques holds the promise of great advances in this area. Cellular energy for silicification and transport comes from aerobic respiration without any direct involvement of photosynthetic energy. As such, diatom silicon metabolism differs from that of other major limiting nutrients such as nitrogen and phosphorous, which are closely linked to photosynthetic metabolism. Cell wall silicification and silicic acid transport are tightly coupled to the cell cycle, which results in a dependency in the extent of silicification on growth rate. Silica dissolution is an important part of diatom cellular silicon metabolism, because dissolution must be prevented in the living cell, and because much of the raw material for mineralization in natural assemblages is supplied by dissolution of dead cells. Perhaps part of the reason for the ecological success of diatoms is due to their use of a silicified cell wall, which has been calculated to impart a substantial energy savings to organisms that have them. However, the growth of diatoms and other siliceous organisms has depleted the oceans of s...

show abstract

Isolation and characterization of peroxisomes from diatoms

Cited by 33 publications

References 21 publications

Evolution of enzymes involved in the photorespiratory 2-phosphoglycolate cycle from cyanobacteria via algae toward plants

Evolution of enzymes involved in the photorespiratory 2-phosphoglycolate cycle from cyanobacteria via algae toward plants

Carbon acquisition by diatoms

Silicon Metabolism in Diatoms: Implications for Growth

Contact Info

Product

Resources

About