TAILIEUCHUNG - Báo cáo khoa học: Weak organic acid stress inhibits aromatic amino acid uptake by yeast, causing a strong influence of amino acid auxotrophies on the phenotypes of membrane transporter mutants

The ability of yeasts to grow in the presence of weak organic acid preservatives is an important cause of food spoilage. Many of the determinants of acetate resistance inSac-charomyces cerevisiae differ from the determinants of resistance to the more lipophilic sorbate and benzoate. Interestingly,we show in this study that hypersensitivity to both acetate and sorbate results when the cells have auxo-trophic requirements for aromatic amino acids. | Eur. J. Biochem. 270 3189-3195 2003 FEBS 2003 doi Weak organic acid stress inhibits aromatic amino acid uptake by yeast causing a strong influence of amino acid auxotrophies on the phenotypes of membrane transporter mutants Bettina E. Bauer1 I Danielle Rossington2 Mehdi Mollapour3 Yasmine Mamnun1 Karl Kuchler1 and Peter W. Piper3 1 Department of Molecular Genetics University and BioCenter of Vienna Austria 2 Unilever Research Colworth Sharnbrook Bedford UK 3Department of Biochemistry and Molecular Biology University College London UK The ability of yeasts to grow in the presence of weak organic acid preservatives is an important cause of food spoilage. Many of the determinants of acetate resistance in Sac-charomyces cerevisiae differ from the determinants of resistance to the more lipophilic sorbate and benzoate. Interestingly we show in this ttody that hypessensiiivity to both acetate and sorbate results when the cells have auxotrophic requirements for aromatic amino acids. In tryptophan biosynthetic pathway mutants this weak acid hypersensitivity is suppressed by supplementing the medium with high levels of tryptophan or in the case of sorbate sensitivity by t1s ssessntt the Tat2p hl hit al íìnhy ttyp-tophan permease. Weak acid stress therefore inhibits uptake of aromatic amino acids from the medium. This allows auxotrophic requirements for these amino acids to strongly influence the resistance phenotypes of mutant strains. This property must be taken into consideration when using these phenotypes to attribute functional assignments to genes. We show that the acetate sensitivity phenotype previously ascribed to yeast mutants lacking the Pdr12p and Azr1p plasma membrane transporters is an artefact arising from the use of trp1 mutant strains. These transporters do not confer resistance to high acetate levels and in prototrophs their presence is actually detrimental for this resistance. Keywords Saccharomyces cerevisiae weak .

• Báo cáo khoa học
• scientific reports
• Report medicine
• traditional medicine
• Structural biochemistry
• oxidation
• bacteria
• collection of scientific reports
• industry reports philosophy of history reports
• reports in literature
• a scientific b shirt
• presentation of scientific reports
• reports on literature
• philosophy statement
• documents
• studies English language and English language communication and English language commercial
• progress reports at scientific collections
• agronomic reports
• reports in physics
• biology reports
• thematic biological
• induced geometry
• mathematical topics
• quantum mechanics
• physics
• reporting mathematics
• physics reports
• livestock reports
• physical reports
• research physicist
• specializing in physics
• mathematical statements
• mathematical equations
• English pronunciation
• presentation report
• agricultural reports
• technical crops
• bio technology
• English reports
• scientific research
• presentation reports
• mathematical knowledge
• reports of mathematics
• represented
• Wilf on packing distinct
• Tur´n density
• mathematical works
• patterns in a permutation
• statements and documents scientific reports
• reports agronomy
• biotechnology
• plants Vietnam
• specialized biological
• microbiological methods
• presenting the report
• anti bacterial properties of shrimp
• energy exchange
• engineering chicken
• Path counting
• random matrix theory
• Even circuits
• prescribed clockwise parity
• Correspondence between
• algorithmic characterizations
• Finding Induced Acyclic
• Random Digraphs
• Nonexistence results
• Hadamard like matrices
• Voltage Graphs
• Group Presentations
• Cages mathematical knowledge
• Dominance Order
• Graphical Partitions
• On the functions
• values in [α(G
• Box With Translates
• Two Given Rectangular Brick
• On the q analogue
• the sum of cubes