Two amino-acid biosynthetic genes are encoded on the plastid genome of the red alga Porphyra umbilicalis

The amino acid sequence of the ferrodoxin of Porphyra umbilicalis was determined by the dansyl-phenyl isothiocyanate method, on peptides obtained by tryptic, chymotryptic and thermolytic digestion of the protein or its CNBr-cleavage fragments. The molecule consists of 98 residues, has an unblocked N-terminus and shows considerable similarity with other plant-type ferredoxins. It is the first reported sequence of a red-algal ferredoxin.

Download Full-text

An hsp70 homolog is encoded on the plastid genome of the red alga, Porphyra umbilicalis

FEBS Letters ◽

10.1016/0014-5793(91)81355-c ◽

1991 ◽

Vol 294 (1-2) ◽

pp. 116-120 ◽

Cited By ~ 22

Author(s):

Michael Reith ◽

Janet Munholland

Keyword(s):

Plastid Genome ◽

Red Alga ◽

Porphyra Umbilicalis

Download Full-text

Amino acid sequence of a ferredoxin from Rhodymenia palmata, a red alga in the florideophyceae

Phytochemistry ◽

10.1016/s0031-9422(00)85023-2 ◽

1984 ◽

Vol 23 (4) ◽

pp. 773-776 ◽

Cited By ~ 5

Author(s):

Katsura Inoue ◽

Toshiharu Hase ◽

Hiroshi Matsubara ◽

Michael P. Fitzgerald ◽

Lyndon J. Rogers

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Red Alga

Download Full-text

The complete amino acid sequence of R-phycocyanin-I alpha and beta subunits from the red alga Porphyridium cruentum. Structural and phylogenetic relationships of the phycocyanins within the phycobiliprotein families

European Journal of Biochemistry ◽

10.1111/j.1432-1033.1994.tb18769.x ◽

1994 ◽

Vol 221 (1) ◽

pp. 563-580 ◽

Cited By ~ 30

Author(s):

Axel DUCRET ◽

Walter SIDLER ◽

Gerhard FRANK ◽

Herbert ZUBER

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Phylogenetic Relationships ◽

Red Alga ◽

Porphyridium Cruentum ◽

Beta Subunits ◽

Complete Amino Acid Sequence

Download Full-text

Translation of the yeast transcriptional activator GCN4 is stimulated by purine limitation: implications for activation of the protein kinase GCN2

Molecular and Cellular Biology ◽

10.1128/mcb.13.8.5099-5111.1993 ◽

1993 ◽

Vol 13 (8) ◽

pp. 5099-5111

Author(s):

R J Rolfes ◽

A G Hinnebusch

Keyword(s):

Amino Acid ◽

Protein Kinase ◽

Transcriptional Activation ◽

Phosphorylation Site ◽

Transcriptional Activator ◽

Translation Initiation Factor ◽

Initiation Factor ◽

Single Amino Acid ◽

Biosynthetic Genes ◽

Transcriptional Activator Protein

The transcriptional activator protein GCN4 is responsible for increased transcription of more than 30 different amino acid biosynthetic genes in response to starvation for a single amino acid. This induction depends on increased expression of GCN4 at the translational level. We show that starvation for purines also stimulates GCN4 translation by the same mechanism that operates in amino acid-starved cells, being dependent on short upstream open reading frames in the GCN4 mRNA leader, the phosphorylation site in the alpha subunit of eukaryotic translation initiation factor 2 (eIF-2 alpha), the protein kinase GCN2, and translational activators of GCN4 encoded by GCN1 and GCN3. Biochemical experiments show that eIF-2 alpha is phosphorylated in response to purine starvation and that this reaction is completely dependent on GCN2. As expected, derepression of GCN4 in purine-starved cells leads to a substantial increase in HIS4 expression, one of the targets of GCN4 transcriptional activation. gcn mutants that are defective for derepression of amino acid biosynthetic enzymes also exhibit sensitivity to inhibitors of purine biosynthesis, suggesting that derepression of GCN4 is required for maximal expression of one or more purine biosynthetic genes under conditions of purine limitation. Analysis of mRNAs produced from the ADE4, ADE5,7, ADE8, and ADE1 genes indicates that GCN4 stimulates the expression of these genes under conditions of histidine starvation, and it appeared that ADE8 mRNA was also derepressed by GCN4 in purine-starved cells. Our results indicate that the general control response is more global than was previously imagined in terms of the type of nutrient starvation that elicits derepression of GCN4 as well as the range of target genes that depend on GCN4 for transcriptional activation.

Download Full-text

Ferredoxin from a Red Alga, Porphyra umbilicalis

European Journal of Biochemistry ◽

10.1111/j.1432-1033.1976.tb10879.x ◽

1976 ◽

Vol 69 (1) ◽

pp. 243-248 ◽

Cited By ~ 21

Author(s):

Peter W. ANDREW ◽

Lyndon J. ROGERS ◽

Donald BOULTER ◽

Barry G. HASLETT

Keyword(s):

Red Alga ◽

Porphyra Umbilicalis

Download Full-text

Association of RAP1 binding sites with stringent control of ribosomal protein gene transcription in Saccharomyces cerevisiae

Molecular and Cellular Biology ◽

10.1128/mcb.11.5.2723-2735.1991 ◽

1991 ◽

Vol 11 (5) ◽

pp. 2723-2735 ◽

Cited By ~ 1

Author(s):

C M Moehle ◽

A G Hinnebusch

Keyword(s):

Gene Expression ◽

Saccharomyces Cerevisiae ◽

Amino Acid ◽

Ribosomal Protein ◽

Binding Sites ◽

Protein Gene ◽

Ribosomal Protein Gene ◽

Ribosomal Protein Genes ◽

Biosynthetic Genes ◽

Stringent Control

An amino acid limitation in bacteria elicits a global response, called stringent control, that leads to reduced synthesis of rRNA and ribosomal proteins and increased expression of amino acid biosynthetic operons. We have used the antimetabolite 3-amino-1,2,4-triazole to cause histidine limitation as a means to elicit the stringent response in the yeast Saccharomyces cerevisiae. Fusions of the yeast ribosomal protein genes RPL16A, CRY1, RPS16A, and RPL25 with the Escherichia coli lacZ gene were used to show that the expression of these genes is reduced by a factor of 2 to 5 during histidine-limited exponential growth and that this regulation occurs at the level of transcription. Stringent regulation of the four yeast ribosomal protein genes was shown to be associated with a nucleotide sequence, known as the UASrpg (upstream activating sequence for ribosomal protein genes), that binds the transcriptional regulatory protein RAP1. The RAP1 binding sites also appeared to mediate the greater ribosomal protein gene expression observed in cells growing exponentially than in cells in stationary phase. Although expression of the ribosomal protein genes was reduced in response to histidine limitation, the level of RAP1 DNA-binding activity in cell extracts was unaffected. Yeast strains bearing a mutation in any one of the genes GCN1 to GCN4 are defective in derepression of amino acid biosynthetic genes in 10 different pathways under conditions of histidine limitation. These Gcn- mutants showed wild-type regulation of ribosomal protein gene expression, which suggests that separate regulatory pathways exist in S. cerevisiae for the derepression of amino acid biosynthetic genes and the repression of ribosomal protein genes in response to amino acid starvation.

Download Full-text

A hierarchy of trans-acting factors modulates translation of an activator of amino acid biosynthetic genes in Saccharomyces cerevisiae

Molecular and Cellular Biology ◽

10.1128/mcb.5.9.2349-2360.1985 ◽

1985 ◽

Vol 5 (9) ◽

pp. 2349-2360 ◽

Cited By ~ 1

Author(s):

A G Hinnebusch

Keyword(s):

Saccharomyces Cerevisiae ◽

Amino Acid ◽

Fusion Transcript ◽

Transcript Level ◽

Amino Acid Starvation ◽

Lacz Fusion ◽

Recessive Mutation ◽

Translational Efficiency ◽

Biosynthetic Genes ◽

Fusion Enzyme

The GCN4 gene encodes a positive effector of amino acid biosynthetic genes in Saccharomyces cerevisiae. Genetic analysis has suggested that GCN4 is regulated by a hierarchy of interacting positive and negative effectors in response to amino acid starvation. Results presented here for a GCN4-lacZ gene fusion support this regulatory model and suggest that the regulators of GCN4 exert their effects primarily at the level of translation of GCN4 mRNA. Both the GCN2 and GCN3 products appear to stimulate translation of GCN4 mRNA in response to amino acid starvation, because a recessive mutation in either gene blocked derepression of GCN4-lacZ fusion enzyme levels but did not reduce the fusion transcript level relative to that in wild-type cells grown in the same conditions. The GCD1 product appears to inhibit translation of GCN4 mRNA because under certain growth conditions, the gcd1-101 mutation led to derepression of the GCN4-lacZ fusion enzyme level in the absence of any increase in the fusion transcript level. In addition, the gcd1-101 mutation suppressed the low translational efficiency of GCN4-lacZ mRNA observed in gcn2- and gcn3- cells. A deletion of four small open reading frames in the 5' leader of GCN4-lacZ mRNA mimicked the effect of a gcd1 mutation and derepressed translation of the fusion transcript in the absence of either starvation conditions or the GCN2 and GCN3 products. By contrast, in a gcd1- strain, the deletion resulted in little additional increase in the translational efficiency of the fusion transcript. These results suggest that GCD1 mediates the translational repression normally exerted by the GCN4 leader sequences and that GCN2 and GCN3 antagonize these negative elements in response to amino acid starvation. The effects of the trans-acting mutations on the translation of GCN4-lacZ mRNA remained intact even when transcription of the fusion gene was placed under the control of the S. cerevisiae GAL1 transcriptional control element.

Download Full-text