Conversion and Distribution of Cobalamin in <i>Euglena gracilis</i> z, with Special Reference to Its Location and Probable Function within Chloroplasts

Isegawa, Yuji; Nakano, Yoshihisa; Kitaoka, Shôzaburô

doi:10.1104/pp.76.3.814

Cited by 29 publications

(10 citation statements)

References 26 publications

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“…In addition to Cbl-dependent enzymes (methionine synthase, methylmalonyl-CoA mutase and ribonucleotide reductase), E. gracilis z contains numerous non-enzymic Cbl-binding proteins, which are distributed in the cytosolic, mitochondrial, chloroplastic and microsomal fractions (Isegawa et al, 1984). Some of these Cblbinding proteins have been purified and characterized (Watanabe et al, 1987a, b ;1988a, b).…”

Section: Introductionmentioning

confidence: 99%

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Watanabe¹,

Nakano

Stupperich

1992

Journal of General Microbiology

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A variety of cobalamin analogues synthesized chemically or microbiologically were used to study the corrinoid specificities of cell growth and the cobalamin uptake system in Euglena gracilis z. Although Euglena could not utilize most of the analogues for cell growth, benzimidazolyl cobamide, cyanocobalamin-@'-phosphate, and cyanocobalamin-6-, -d-and -e-monocarboxylates had effects similar to that of cyanocobalamin on cell growth. It is suggested that Euglena cells have the ability to synthesize 'complete cobalamin' from the acid derivatives (amidation reaction) and/or the phosphate derivative (dephosphorylation reaction). Inhibition of uptake of radiolabelled cyanocobalamin caused by addition of various analogues indicates that both the d o w e r axial ligand (the cobalt-coordinated nucleotide) and the (6)-propionamide side-chain of the cobalamin molecule are essential for the cobalamin uptake system in Euglena. These results indicate that there are different corrinoid specificities for cell growth and the cobalamin uptake system in E. gradis z.

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Section: Introductionmentioning

confidence: 99%

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Watanabe¹,

Nakano

Stupperich

1992

Journal of General Microbiology

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“…The thetic activity was not restored and after cell division ceased the activity was restored, indicating that E. gracilis requires Cbl for normal photosynthesis independently of cell division. Figure 5 shows the effect on the photosynthetic activity after supplementing 4 (8). The lag observed in the recovery of photosynthetic activity after addition of methionine might be due to a number of factors.…”

Section: Resultsmentioning

confidence: 99%

“…In Euglena gracilis the physiological function of Cbl2 has not been well understood, although Cbl is essential for growth, is rapidly accumulated in the celLs (2,18) and is converted to coenzyme forms in this organism (8). Euglena cels, when grown on a CN-Cbl-limited medium (below 50 ng CN-CbL-1), show increases in chloroplast number and concomitant increases in cell components such as Chl, protein, RNA and DNA (3, 9); CN-Cbl-limited cells return to the normal state within 24 h after raising the CN-Cbl level to normal (2).…”

mentioning

confidence: 99%

Photosynthesis of Euglena gracilis under Cobalamin-Sufficient and -Limited Growing Conditions

Isegawa¹,

Nakano²,

Kitaoka³

1987

Plant Physiol.

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Subeeilular Fractionation and Pumification of Chloroplasts. Partial trypsin digestion ofthe pellicle followed by mild mechanical disruption of Euglena ceUs and subcellular frationation by differential centifugation were conducted according to Shigeoka et al. (19).A suspension of chloroplasts was layered on the top of continuous Percoll (Lot No. 4634) gradients and centrifuged in a swingout rotor (Hitachi Reactions of Photosynthesis. Photosynthesis resulted in net 02 evolution from cells, which were cultured in the dark in the presence of Cbl and then in the light with limiting or supplementing CbL was measured with a Kalbani-type oxygen electrode (Kyusui Kaaku Co.) in 2 ml of a reaction mixture containing an aliquot ofthe cell culture and 25 mm NaHCO3, 1 mM MgC12, and 50 mmt potassium phosphate buffer (pH 7.8). The mixture which contained 60 to 100 ug Chl ml-', was incubated at 25°C and 10,000 lux with wolfram lamp. 4C02 fixation was carried out under the same conditions as described above except that 10 mm (0.4 MCi) (final concentration) NaH'4C03 was added instead of 25 mm NaHCO3. A sample of 0.2 ml was withdrawn after a definite period through Eppendorf pipette and injected into a vial containing 0.3 ml of 0.3 N HCI. The vial was shaken for 30 mn to remove free`4C02 and the fixed radioactivity in the sample was counted with Aloka LSC 903 scintillation counter.

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“…gracilis Z contains numerous nonenzymatic B12-binding proteins, which are distributed in the cytosolic, mitochondrial, chloroplastic, and microsomal fractions (Isegawa et al 1984). Some of these B12-binding proteins have been purified and characterized (Watanabe et al 1987a(Watanabe et al , b, 1988b.…”

Section: Vitamin B12mentioning

confidence: 98%

Biochemistry and Physiology of Vitamins in Euglena

Watanabe

Yoshimura

Shigeoka

2017

Advances in Experimental Medicine and Biology

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Euglena gracilis Z requires vitamins B1 and B12 for growth. It takes up and accumulates large amounts of these exogenous vitamins through energy-dependent active transport systems. Except for these essential vitamins, E. gracilis Z has the ability to synthesize all human vitamins. Euglena synthesizes high levels of antioxidant vitamins such as vitamins C and E, and, thus, are used as nutritional supplements for humans and domestic animals. Methods to effectively produce vitamins in Euglena have been investigated.Previous biochemical studies indicated that E. gracilis Z contains several vitamin-related novel synthetic enzymes and metabolic pathways which suggests that it is a highly suitable organism for elucidating the physiological functions of vitamins in comparative biochemistry and biological evolution. E. gracilis Z has an unusual biosynthetic pathway for vitamin C, a hybrid of the pathways found in animals and plants. This chapter presents up-to-date information on the biochemistry and physiological functions of vitamins in this organism.

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Conversion and Distribution of Cobalamin in Euglena gracilis z, with Special Reference to Its Location and Probable Function within Chloroplasts

Abstract: Cobalamin is essentially required for growth by Eugkna gracilis and shown to be converted to coenzyme forms promptly after feeding cyanocobalamin. Concentrations of coenzymes, methylcobalamin, and 5'-de-

Cited by 29 publications

References 26 publications

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Photosynthesis of Euglena gracilis under Cobalamin-Sufficient and -Limited Growing Conditions

Biochemistry and Physiology of Vitamins in Euglena

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