Wei-yeh Wang

Learn More
Protochlorophyllide (Pchilide) photoconversion, a key step in the biosynthesis of chlorophyll, is catalyzed by the enzyme NADPH: Pchlide oxidoreductase. We have previously shown that the pc-1 mutation of Chlamydomonas reinhardtii causes a defect in photoconversion in vivo. The double mutant pc-1 y-7 failed to photoconvert Pchlide to chlorophyllide, whereas(More)
We have developed a procedure for the isolation of Chlamydomonas reinhardtii mutants defective in light-dependent protochlorophyllide reduction (photoconversion), a key step in the biosynthesis of chlorophyll. Mutants were isolated by mutagenizing y-1-4, a temperature-sensitive yellow mutant blocked in the alternative light-independent protochlorophyllide(More)
Three phenotypically ‘yellow’, mendelian mutants of Chlamydomonas reinhardtii have been isolated and tested for allelism with the yellow mutant v-1a 1 and with each other. The three mutants represent three new yellow loci, two of which are located on linkage group I. Like y-1a, the mutants accumulate protochlorophyllide when grown under dim light, but have(More)
Simian virus 40 (SV40) small t antigen (t) can activate transcription from certain RNA polymerase II and III promoters (M. Loeken, I. Bikel, D. M. Livingston, and J. Brady, Cell 55:1171-1177, 1988). Here we report a new function of t, its ability to repress human c-fos promoter and AP-1 transcriptional activity in CV-1P cells. This function is the product(More)
We have isolated and genetically characterized 10 mutants of Chlamydomonas reinhardtii carrying single, mendelian, temperature-sensitive yellow mutations. The mutants have a yellow phenotype at the restrictive temperature (33°C), but have a wildtype phenotype at the permissive temperature (25°C). Based on complementation and recombination tests, the ten(More)
A group of chlorophyll deficient mutants (br s mutants) of Chlamydomonas accumulates protoporphyrin and has poorly developed chloroplast membrane systems (Wang et al. 1974). In order to determine whether a poorly developed chloroplast membrane system is the reason for, or the result of, the inability of the br s mutants to metabolize protoporphyrin to(More)
In this report we describe two nonallelic Mendelian protoporphyrin accumulating mutants brs-I and bre-1. Results of experiments with these mutants lead us to postulate that porphyrin biosynthesis branches into light and dark steps between protoporphyrin-IX and magnesium protoporphyrin. We hypothesize that the br e locus controls a dark step while the br s(More)
A Mendelian mutant r-1 in chlamydomonas reinhardtii has been shown to make the synthesis of δ-aminolevulinic acid (ALA) insensitive to inhibition by protoporphyrin. We have now combined the r-1 mutant with the protochlorophyllideaccumulating mutant y-1. From the phenotype of the double mutant y-1 r-1 and the phenocopy produced by feeding ALA to y-1, we(More)
A chlorophyll-deficient mutant, br s -1, of Chlamydomonas reinhardtii has been shown to accumulate low levels of an intermediate, protoporphyrin (PROTO), and to form light-brown colonies. A double mutant, br s -1 r-1, accumulates 15-fold more PROTO than br s -1 and forms dark-brown colonies. Enzymes synthesizing the first intermediate of chlorophyll,(More)
Twenty-three spontaneous yellow mutants were isolated from two stable green strains of the unicellular green alga Chlamydomonas reinhardtii. Genetic characterization indicated that 22 of 23 mutants had a mutation at the y-1 locus, and all 22 y-1 alleles were unstable. Crosses designed to follow the inheritance of instability at the y-1 locus showed that(More)
  • 1