Molecular Basis for Transmission Barrier and Interference between Closely Related Prion Proteins in Yeast

Replicating amyloids, called prions, are responsible for transmissible neurodegenerative diseases in mammals and some heritable phenotypes in fungi. The transmission of prions between species is usually inhibited, being highly sensitive to small differences in amino acid sequence of the prion-forming proteins. To understand the molecular basis of this prion interspecies barrier, we studied the transmission of the [PSI+] prion state from Sup35 of Saccharomyces cerevisiae to hybrid Sup35 proteins with prion-forming domains from four other closely related Saccharomyces species. Whereas all the hybrid Sup35 proteins could adopt a prion form in S. cerevisiae, they could not readily acquire the prion form from the [PSI+] prion of S. cerevisiae. Expression of the hybrid Sup35 proteins in S. cerevisiae [PSI+] cells often resulted in frequent loss of the native [PSI+] prion. Furthermore, all hybrid Sup35 proteins showed different patterns of interaction with the native [PSI+] prion in terms of co-polymerization, acquisition of the prion state, and induced prion loss, all of which were also dependent on the [PSI+] variant. The observed loss of S. cerevisiae [PSI+] can be related to inhibition of prion polymerization of S. cerevisiae Sup35 and formation of a non-heritable form of amyloid. We have therefore identified two distinct molecular origins of prion transmission barriers between closely sequence-related prion proteins: first, the inability of heterologous proteins to co-aggregate with host prion polymers, and second, acquisition by these proteins of a non-heritable amyloid fold.

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The complete amino acid sequence of copper, zinc superoxide dismutase from Saccharomyces cerevisiae

Carlsberg Research Communications ◽

10.1007/bf02906155 ◽

1979 ◽

Vol 44 (4) ◽

pp. 201-217 ◽

Cited By ~ 88

Author(s):

Jack T. Johansen ◽

Carsten Overballe-Petersen ◽

Brian Martin ◽

Villy Hasemann ◽

Ib Svendsen

Keyword(s):

Saccharomyces Cerevisiae ◽

Superoxide Dismutase ◽

Amino Acid ◽

Amino Acid Sequence ◽

Copper Zinc Superoxide Dismutase ◽

Complete Amino Acid Sequence ◽

Zinc Superoxide Dismutase ◽

Copper Zinc

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Sequence of the Saccharomyces cerevisiae CATI gene and amino acid sequence of catalase A derived from it

European Journal of Biochemistry ◽

10.1111/j.1432-1033.1988.tb14263.x ◽

1988 ◽

Vol 176 (1) ◽

pp. 159-163 ◽

Cited By ~ 55

Author(s):

Gerald CHOEN ◽

Winfried RAPATZ ◽

Helmut RUIS

Keyword(s):

Saccharomyces Cerevisiae ◽

Amino Acid ◽

Amino Acid Sequence

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Temperature and Proteins: Little Things Can Mean a Lot

Physiology ◽

10.1152/physiologyonline.1996.11.2.72 ◽

1996 ◽

Vol 11 (2) ◽

pp. 72-77 ◽

Cited By ~ 1

Author(s):

GN Somero

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Protein Stability ◽

Active Sites ◽

Protein Structures ◽

Free Energies ◽

Adaptive Changes ◽

Highly Sensitive

Protein structures are highly sensitive to temperature because their net free energies of stabilization are low, about equal to energies associated with formation of a few noncovalent ("weak") bonds. Temperature-adaptive changes in protein stability and fucntion may result from minor changes in amino acid sequence at regions outside active sites and from accumulation of stabilizing solutes in the cell.

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Gene RRN4 in Saccharomyces cerevisiae encodes the A12.2 subunit of RNA polymerase I and is essential only at high temperatures.

Molecular and Cellular Biology ◽

10.1128/mcb.13.1.114 ◽

1993 ◽

Vol 13 (1) ◽

pp. 114-122 ◽

Cited By ~ 59

Author(s):

Y Nogi ◽

R Yano ◽

J Dodd ◽

C Carles ◽

M Nomura

Keyword(s):

Saccharomyces Cerevisiae ◽

Amino Acid ◽

Amino Acid Sequence ◽

Rna Polymerase ◽

Rna Polymerase I ◽

Rrna Genes ◽

Temperature Sensitive ◽

Polymerase I ◽

Temperature Sensitive Phenotype ◽

Null Mutants

We have previously isolated mutants of Saccharomyces cerevisiae that are primarily defective in transcription of 35S rRNA genes by RNA polymerase I and have identified genes (RRN1 to RRN9) involved in this process. We have now cloned the RRN4 gene by complementation of the temperature-sensitive phenotype of the rrn4-1 mutant and have determined its complete nucleotide sequence. The following results demonstrate that the RRN4 gene encodes the A12.2 subunit of RNA polymerase I. First, RRN4 protein expressed in Escherichia coli reacted with a specific antiserum against A12.2. Second, amino acid sequences of three tryptic peptides obtained from A12.2 were determined, and these sequences are found in the deduced amino acid sequence of the RRN4 protein. The amino acid sequence of the RRN4 protein (A12.2) is similar to that of the RPB9 (B12.6) subunit of yeast RNA polymerase II; the similarity includes the presence of two putative zinc-binding domains. Thus, A12.2 is a homolog of B12.6. We propose to rename the RRN4 gene RPA12. Deletion of RPA12 produces cells that are heat but not cold sensitive for growth. We have found that in such null mutants growing at permissive temperatures, the cellular concentration of A190, the largest subunit of RNA polymerase I, is lower than in the wild type. In addition, the temperature-sensitive phenotype of the rpa12 null mutants can be partially suppressed by RPA190 (the gene for A190) on multicopy plasmids. These results suggest that A12.2 plays a role in the assembly of A190 into a stable polymerase I structure.

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Suppressor analysis of temperature-sensitive mutations of the largest subunit of RNA polymerase I in Saccharomyces cerevisiae: a suppressor gene encodes the second-largest subunit of RNA polymerase I.

Molecular and Cellular Biology ◽

10.1128/mcb.11.2.754 ◽

1991 ◽

Vol 11 (2) ◽

pp. 754-764 ◽

Cited By ~ 42

Author(s):

R Yano ◽

M Nomura

Keyword(s):

Saccharomyces Cerevisiae ◽

Amino Acid ◽

Amino Acid Sequence ◽

Rna Polymerase ◽

Binding Domain ◽

Rna Polymerase I ◽

Zinc Binding ◽

Temperature Sensitive ◽

Polymerase I ◽

Zinc Binding Domain

The SRP3-1 mutation is an allele-specific suppressor of temperature-sensitive mutations in the largest subunit (A190) of RNA polymerase I from Saccharomyces cerevisiae. Two mutations known to be suppressed by SRP3-1 are in the putative zinc-binding domain of A190. We have cloned the SRP3 gene by using its suppressor activity and determined its complete nucleotide sequence. We conclude from the following evidence that the SRP3 gene encodes the second-largest subunit (A135) of RNA polymerase I. First, the deduced amino acid sequence of the gene product contains several regions with high homology to the corresponding regions of the second-largest subunits of RNA polymerases of various origins, including those of RNA polymerase II and III from S. cerevisiae. Second, the deduced amino acid sequence contains known amino acid sequences of two tryptic peptides from the A135 subunit of RNA polymerase I purified from S. cerevisiae. Finally, a strain was constructed in which transcription of the SRP3 gene was controlled by the inducible GAL7 promoter. When this strain, which can grow on galactose but not on glucose, was shifted from galactose medium to glucose medium, a large decrease in the cellular concentration of A135 was observed by Western blot analysis. We have also identified the specific amino acid alteration responsible for suppression by SRP3-1 and found that it is located within the putative zinc-binding domain conserved among the second-largest subunits of eucaryotic RNA polymerases. From these results, it is suggested that this putative zinc-binding domain is in physical proximity to and interacts with the putative zinc-binding domain of the A190 subunit.

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Serine and threonine catabolism in Saccharomyces cerevisiae: the CHA1 polypeptide is homologous with other serine and threonine dehydratases.

Genetics ◽

10.1093/genetics/131.3.531 ◽

1992 ◽

Vol 131 (3) ◽

pp. 531-539 ◽

Cited By ~ 6

Author(s):

C Bornaes ◽

J G Petersen ◽

S Holmberg

Keyword(s):

Saccharomyces Cerevisiae ◽

Amino Acid ◽

Amino Acid Sequence ◽

Transcription Initiation ◽

Open Reading Frame ◽

Predicted Amino Acid Sequence ◽

S1 Nuclease ◽

Reading Frame ◽

Threonine Dehydratase ◽

Nuclease Mapping

Abstract The catabolic L-serine (L-threonine) dehydratase of Saccharomyces cerevisiae allows the yeast to grow on media with L-serine or L-threonine as sole nitrogen source. Previously we have cloned the CHA1 gene by complementation of a mutant, cha1, lacking the dehydratase activity. Here we present the DNA sequence of a 1,766-bp fragment of the CHA1 region encompassing an open reading frame of 1080 bp. Comparison of the predicted amino acid sequence of the CHA1 polypeptide with that of other serine/threonine dehydratases revealed several blocks of sequence homology. Thus, the amino acid sequence of rat liver serine dehydratase (SDH2) and the CHA1 polypeptide are 44% homologous allowing for conservative substitutions, while 36% similarity is found between the catabolic threonine dehydratase (tdcB) of Escherichia coli and the CHA1 protein. This strongly suggests that CHA1 is the structural gene for the yeast catabolic serine (threonine) dehydratase. S1-nuclease mapping of the CHA1 mRNA ends showed a major transcription initiation site corresponding to an untranslated leader of about 19 nucleotides, while a major polyadenylation site was located about 86 nucleotides downstream from the open reading frame. Furthermore, we have mapped the chromosomal position of the CHA1 gene to less than 0.5 kb centromere proximal to HML on the left arm of chromosome III.

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Molecular basis for congenital deficiency of alpha 2-plasmin inhibitor. A frameshift mutation leading to elongation of the deduced amino acid sequence.

Journal of Clinical Investigation ◽

10.1172/jci114057 ◽

1989 ◽

Vol 83 (5) ◽

pp. 1598-1604 ◽

Cited By ~ 28

Author(s):

O Miura ◽

S Hirosawa ◽

A Kato ◽

N Aoki

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Molecular Basis ◽

Frameshift Mutation ◽

Congenital Deficiency ◽

Plasmin Inhibitor

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The Saccharomyces cerevisiae ACP2 gene encodes an essential HMG1-like protein

Molecular and Cellular Biology ◽

10.1128/mcb.8.3.1282-1289.1988 ◽

1988 ◽

Vol 8 (3) ◽

pp. 1282-1289

Author(s):

W Haggren ◽

D Kolodrubetz

Keyword(s):

Saccharomyces Cerevisiae ◽

Amino Acid ◽

Amino Acid Sequence ◽

High Mobility ◽

Hmg Proteins ◽

Gene Encoding ◽

Yeast Saccharomyces Cerevisiae ◽

Dna Library ◽

Associated Proteins ◽

Genomic Dna Library

The high-mobility-group (HMG) proteins, a group of nonhistone chromatin-associated proteins, have been extensively characterized in higher eucaryotic cells. To test the biological function of an HMG protein, we have cloned and mutagenized a gene encoding an HMG-like protein from the yeast Saccharomyces cerevisiae. A yeast genomic DNA library was screened with an oligonucleotide designed to hybridize to any yeast gene containing an amino acid sequence conserved in several higher eucaryotic HMG proteins. DNA sequencing and Northern (RNA) blot analysis revealed that one gene, called ACP2 (acidic protein 2), synthesizes a poly(A)+ RNA in S. cerevisiae which encodes a 27,000-molecular-weight protein whose amino acid sequence is homologous to those of calf HMG1 and HMG2 and trout HMGT proteins. Standard procedures were used to construct a diploid yeast strain in which one copy of the ACP2 gene was mutated by replacement with the URA3 gene. When this diploid was sporulated and dissected, only half of the spores were viable. About half of the nonviable spores proceeded through two or three cell divisions and then stopped dividing; the rest did not germinate at all. None of the viable spores contained the mutant ACP2 gene, thus proving that the protein encoded by ACP2 is required for cell viability. The results presented here demonstrate that an HMG-like protein has an essential physiological function.

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