δ-Aminolevulinic acid transport in Saccharomyces cerevisiae

Moretti, Mariana Bermúdez; García, Sara Mallén; Stella, Carlos A.; Ramos, Eugénia; Batlle, Alcira

doi:10.1016/0020-711x(88)90325-4

Cited by 25 publications

(7 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The latter conclusion is based on the observations that cellular uptake was concentration dependent, temperature independent and unaffected by the presence of serum in the culture medium. These results differ from those of Moretti et al, who reported an active transport of 6-ALA in Saccharomyces cerevisiae (25). They found that inhibitors of ATP synthesis reduce the accumulation of 6-ALA in this yeast.…”

Section: Discussioncontrasting

confidence: 99%

Time‐dependent Intracellular Accumulation of 5‐Aminolevulinic Acid, Induction of Porphyrin Synthesis and Subsequent Phototoxicity

Gibson

Havens²,

Foster³

et al. 1997

Photochem & Photobiology

View full text Add to dashboard Cite

Photodynamic therapy (PDT), a novel treatment for a variety of human malignancies, usually consists of visible light irradiation of lesions following the systemic administration of a photosensitizer. Induction of the endogenous photosensitizer protoporphyrin IX by the systemic or topical administration of delta-aminolevulinic acid (delta-ALA) is being investigated for use in PDT. We have determined that the incubation of two human and two rodent tumor cell lines in culture with delta-ALA over a 24 h period results in an increase in the accumulation of fluorescent porphyrins in all of these cell lines. However, the two human cell lines produce fluorescent porphyrin at different rates from those seen in the rodent cell lines. The uptake of 14C-delta-ALA was concentration dependent, similar for all the cell lines studied and rapidly reached an intra/extracellular equilibrium after delta-ALA was added to the culture medium. The increase in intracellular fluorescent porphyrin was dependent on the level of delta-ALA in the medium and the incubation time and was directly related to the phototoxicity observed upon exposure of cultured monolayers to light. The data demonstrate that equivalent levels of phototoxicity can be attained by exposing cells to 0.04 mM delta-ALA for 24 h or to 0.5 mM delta-ALA for 2 h. These findings may have implications for optimization of PDT treatment regimens that use delta-ALA.

show abstract

Section: Discussioncontrasting

confidence: 99%

Time‐dependent Intracellular Accumulation of 5‐Aminolevulinic Acid, Induction of Porphyrin Synthesis and Subsequent Phototoxicity

Gibson

Havens²,

Foster³

et al. 1997

Photochem & Photobiology

View full text Add to dashboard Cite

show abstract

“…Our present experimental results do not permit us to infer whether the endogenous synthesis of ALA in dense cultures involves transcriptional or translational events, and further work will be necessary to establish the nature of the mechanism involved. However, the failure of GABA to inhibit tetrapyrrole synthesis suggests that the transporter demonstrated in Saccharomyces cerevisiae (Moretti et al, 1993(Moretti et al, , 1995 is not involved. It is possible that the uptake is non-specific and that intracellular levels of ALA are controlled by an externalizing pump mechanism.…”

Section: Discussionmentioning

confidence: 99%

“…In a previous paper (Fukuda et al, 1993), we reported on the kinetics of porphyrin accumulation in ALA-stimulated cells, in which we showed that the total porphyrin synthesized is a function of the external ALA concentration and the incubation time, and that the rate of porphyrin synthesis increased as a function of the time of exposure to ALA. Recent studies in Saccharomyces cerevisiae (Moretti et al, 1993(Moretti et al, , 1995 have gone some way to establish the nature of the transport system in yeast, but relatively little is known about the mechanism and control of ALA uptake in mammalian cells. In this paper, we examine the uptake of ALA and its relationship with tetrapyrrole metabolism in an established line of mammalian epithelial cells.…”

mentioning

confidence: 99%

Stimulation of tetrapyrrole synthesis in mammalian epithelial cells in culture by exposure to aminolaevulinic acid

Washbrook

Fukuda²,

Battle³

et al. 1997

Br J Cancer

View full text Add to dashboard Cite

Summary Tetrapyrrole synthesis in CNCM-1221 cells exposed to 0.6 mm aminolaevulinic acid (ALA) was found to be approximately linear over a 6-h period of incubation. The rate was not significantly affected by cell density over a range of 0.015 to 0.15 x 106 cells cm-2 (final cell density). Tetrapyrrole synthesis was not affected by GABA or glutamic acid in concentrations up to 6 mm and 2.72 mm respectively, suggesting that these amino acids, which are similar in structure to ALA, do not competitively inhibit the ALA uptake pathway in these cells. Pre-exposure to haem arginate (up to 100 gM) was inhibitory, presumably by suppression (through the inhibition of ALA synthase) of an endogenous component of the response. The ALA-stimulated response was not modified by co-exposure to AIA (up to 100 mg ml-'). Despite significant reduction of protein synthesis, the porphyrinogenic response of cells exposed to ALA was unaffected by cycloheximide (10 gg ml-') or actinomycin D (10 gg ml-') even when cells were preincubated with these agents for 3 h before ALA exposure. Fetal bovine serum (10%) inhibited tetrapyrrole synthesis by 30% but increased the rate of porphyrin export by cells by a factor of 1.5. The uptake of [14C]ALA was shown to be strongly influenced by the density of the cultures. In dense cultures (final cell density of approximately 0.15 x 106 cells cm-2), the ALA uptake rate was less than 0.8 compared with a maximum rate of 4.2 fmol per cell h-' at a cell density of 0.02 x 106 cells cm-2. Since tetrapyrrole synthesis is less affected than ALA uptake by cell density, the resultant discrepancy in ALA incorporation occurrng in dense cultures implies that endogenous ALA synthesis is induced in these cells. ALA uptake was not affected by cycloheximide or actinomycin D in serum-free conditions. However, fetal bovine serum decreased external ALA uptake by about 50%. This effect was abrogated by preincubation with cycloheximide.

show abstract

“…Exogenous ALA fed to plant leaves is metabolized through chlorophyll synthesis located in plastids. ALA uptake into bacterial and yeast cells is mediated by a dipeptide permease (Elliott, 1993;Moretti et aL, 1993). However, detection of immune-reacting ALA-S in the soluble fraction of plastids and the plastidal ALA-S activity is consistent with translocation of the foreign protein into chloroplasts by means of the transit sequence of the small subunit of ribulose bisphosphate carboxylase (preSSU).…”

Section: In Which Subcellular Compartment Does Ala-s Form Ala?mentioning

confidence: 99%

Yeast 5‐aminolevulinate synthase provides additional chlorophyll precursor in transgenic tobacco

Zavgorodnyaya

Papenbrock

Grimm³

1997

The Plant Journal

View full text Add to dashboard Cite

SummarySynthesis of the tetrapyrrole precursor 5-aminolevulinate (ALA} in plants starts with glutamate and is a tRNAdependent pathway consisting of three enzymatic steps localized in plastids. In animals and yeast, ALA is formed in a single step from succinyl CoA and glycine by aminolevulinate synthase (ALA-S) in mitochondria. A gene encoding a fusion protein of yeast ALA-S with an aminoterminal transit sequence for the small subunit of ribulose bisphosphate carboxylase was introduced into the genome of wild-type tobacco and a chlorophyll-deficient transgenic line expressing glutamate 1-semi-aldehyde aminotransferase (GSA-AT) antisense RNA. Expression of ALA-S in the GSA-AT antisense transgenic line provided green-pigmented co-transformants similar to wild-type in chlorophyll content, while transformants derived from wild-type plants did not show phenotypical changes. The capacity to synthesize ALA and chlorophyll was increased in transformed plants, indicating a contribution of ALA-S to the ALA supply for chlorophyll synthesis. ALA-S activity was detected in plastids of the transformants. Preliminary evidence is presented that succinyl CoA, the substrate for ALA-S, can be synthesized and metabolized in plastids. The transgenic plants formed chlorophyll in the presence of gabaculine, an inhibitor of GSA-AT. Steady-state RNA and protein levels and, consequently, the enzyme activity of GSA-AT were reduced in plants expressing ALA-S, In analogy to the light-dependent ALA synthesis attributed to feedback regulation, a mechanism at the level of intermediates or tetrapyrrole end-products is proposed, which co-ordinates the need for heme and chlorophyll precursors and restricts synthesis of ALA by regulating GSA-AT gene expression. The genetically engineered tobacco plants containing the yeast ALA-S activity demonstrate functional complementation of the catalytic activity of the plant ALA-synthesizing pathway and open strategies for producing tolerance against inhibitors of the C5 pathway.

show abstract

δ-Aminolevulinic acid transport in Saccharomyces cerevisiae

Cited by 25 publications

References 16 publications

Time‐dependent Intracellular Accumulation of 5‐Aminolevulinic Acid, Induction of Porphyrin Synthesis and Subsequent Phototoxicity

Time‐dependent Intracellular Accumulation of 5‐Aminolevulinic Acid, Induction of Porphyrin Synthesis and Subsequent Phototoxicity

Stimulation of tetrapyrrole synthesis in mammalian epithelial cells in culture by exposure to aminolaevulinic acid

Yeast 5‐aminolevulinate synthase provides additional chlorophyll precursor in transgenic tobacco

Contact Info

Product

Resources

About