Genes encoding RNA-binding proteins are diverse and abundant in eukaryotic genomes. Although some have been shown to have roles in post-transcriptional regulation of the expression of specific genes, few of these proteins have been studied systematically. We have used an affinity tag to isolate each of the five members of the Puf family of RNA-binding proteins in Saccharomyces cerevisiae and DNA microarrays to comprehensively identify the associated mRNAs. Distinct groups of 40–220 different mRNAs with striking common themes in the functions and subcellular localization of the proteins they encode are associated with each of the five Puf proteins: Puf3p binds nearly exclusively to cytoplasmic mRNAs that encode mitochondrial proteins; Puf1p and Puf2p interact preferentially with mRNAs encoding membrane-associated proteins; Puf4p preferentially binds mRNAs encoding nucleolar ribosomal RNA-processing factors; and Puf5p is associated with mRNAs encoding chromatin modifiers and components of the spindle pole body. We identified distinct sequence motifs in the 3′-untranslated regions of the mRNAs bound by Puf3p, Puf4p, and Puf5p. Three-hybrid assays confirmed the role of these motifs in specific RNA–protein interactions in vivo. The results suggest that combinatorial tagging of transcripts by specific RNA-binding proteins may be a general mechanism for coordinated control of the localization, translation, and decay of mRNAs and thus an integral part of the global gene expression program.

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Extensive Association of Functionally and Cytotopically Related mRNAs with Puf Family RNA-Binding Proteins in Yeast

Plant cells are immobile; thus, plant growth and development depend on cell expansion rather than cell migration. The molecular mechanism by which the plasma membrane initiates changes in the cell expansion rate remains elusive. We found that a secreted peptide, RALF (rapid alkalinization factor), suppresses cell elongation of the primary root by activating the cell surface receptor FERONIA in Arabidopsis thaliana. A direct peptide-receptor interaction is supported by specific binding of RALF to FERONIA and reduced binding and insensitivity to RALF-induced growth inhibition in feronia mutants. Phosphoproteome measurements demonstrate that the RALF-FERONIA interaction causes phosphorylation of plasma membrane H+–adenosine triphosphatase 2 at Ser899, mediating the inhibition of proton transport. The results reveal a molecular mechanism for RALF-induced extracellular alkalinization and a signaling pathway that regulates cell expansion.

/pdf/a-peptide-hormone-and-its-receptor-protein-kinase-regulate-3330ive7as.pdf

A Peptide Hormone and Its Receptor Protein Kinase Regulate Plant Cell Expansion

P-type ATPases are ion pumps that carry out many fundamental processes in biology and medicine, ranging from the generation of membrane potential to muscle contraction and the removal of toxic ions from cells. Making use of the energy stored in ATP, they transport specific ions across the cell membrane against a concentration gradient. Recent X-ray structures and homology models of P-type pumps now provide a basis for understanding the molecular mechanism of ATP-driven ion transport.

Biology, structure and mechanism of P-type ATPases

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/S0014-5793%2801%2902503-0

Global gene expression during short‐term ethanol stress in Saccharomyces cerevisiae

Acknowledgements. Introduction. A: Environment. 1. Global impact of salinity and agricultural ecosystems M.G. Pitman, A. Lauchli. 2. Salinity in the soil environment K.K. Tanji. 3. Salinity, halophytes and salt affected natural ecosystems S.-W. Breckle. B: Organisms. 4. Adaptation of halophilic Archaea to life at high salt concentrations A. Oren. 5. Adaptation of the haloterant alga Dunaliella to high salinity U. Pick. 6. Mangroves U. Luttge. C: Mechanisms. 7. Ultrastructural effects of salinity in higher plants H.-W. Koyro. 8. Intra- and inter-cellular compartmentation of ions - a study in specificity and plasticity G. Wyn Jones, J. Gorham. 9. Salinity, osmolytes and compatible solutes D. Rhodes, et al. 10. Sodium-calcium interactions under salinity stress G.R. Cramer. 11. Salinity and nitrogen nutrition W.R. Ullrich. 12. Pressure probe measurements of the driving forces for water transport in intact higher plants: effects of transpiration and salinity U. Zimmermann, et al. 13. Salinity, growth and phytohormones R. Munns. 14. The adaptive potential of plant development: evidence from the response to salinity G.N. Amzallag. D: Photosynthesis. 15. Influence of salinity on photosynthesis of halophytes C.E. Lovelock, M.C. Ball. 16. Performance of plants with C4-carboxylation modes of photosynthesis under salinity U. Luttge. 17. Induction of Crassulacean acid metabolism by salinity -- molecular aspects H.J. Bohnert.E: Molecules. 18. Function of membrane transport systems under salinity: plasma membrane L. Reinhold, M. Guy. 19. Function of membrane transport systems under salinity: tonoplast M. Binzel, R. Ratajczak. 20. Genetics of salinity responses and plant breeding J. Gorham, G.Wyn Jones. 21. Halotolerance genes in yeast R. Serrano. 22. The long and winding road to haloterance genes A. Maggio, et al. Index.

Salinity : environment - plants - molecules

The regulation of electrical membrane potential is a fundamental property of living cells. This biophysical parameter determines nutrient uptake, intracellular potassium and turgor, uptake of toxic cations, and stress responses. In fungi and plants, an important determinant of membrane potential is the electrogenic proton-pumping ATPase, but the systems that modulate its activity remain largely unknown. We have characterized two genes from Saccharomyces cerevisiae, PTK2 and HRK1 (YOR267c), that encode protein kinases implicated in activation of the yeast plasma membrane H(+)-ATPase (Pma1) in response to glucose metabolism. These kinases mediate, directly or indirectly, an increase in affinity of Pma1 for ATP, which probably involves Ser-899 phosphorylation. Ptk2 has the strongest effect on Pma1, and ptk2 mutants exhibit a pleiotropic phenotype of tolerance to toxic cations, including sodium, lithium, manganese, tetramethylammonium, hygromycin B, and norspermidine. A plausible interpretation is that ptk2 mutants have a decreased membrane potential and that diverse cation transporters are voltage dependent. Accordingly, ptk2 mutants exhibited reduced uptake of lithium and methylammonium. Ptk2 and Hrk1 belong to a subgroup of yeast protein kinases dedicated to the regulation of plasma membrane transporters, which include Npr1 (regulator of Gap1 and Tat2 amino acid transporters) and Hal4 and Hal5 (regulators of Trk1 and Trk2 potassium transporters).

Regulation of yeast H(+)-ATPase by protein kinases belonging to a family dedicated to activation of plasma membrane transporters.

Head morphogenesis genes of the Bacillus subtilis bacteriophage SPP1.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/S0014-5793%2897%2900721-7

Glucose activation of the yeast plasma membrane H+-ATPase requires the ubiquitin-proteasome proteolytic pathway.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/S0014-5793%2897%2901478-6

Natalia de la Fuente

Papers

Regulation of yeast H(+)-ATPase by protein kinases belonging to a family dedicated to activation of plasma membrane transporters.

Head morphogenesis genes of the Bacillus subtilis bacteriophage SPP1.

Glucose activation of the yeast plasma membrane H+-ATPase requires the ubiquitin-proteasome proteolytic pathway.

Yeast gene YOR137c is involved in the activation of the yeast plasma membrane H+-ATPase by glucose

The cell wall integrity/remodeling MAPK cascade is involved in glucose activation of the yeast plasma membrane H(+)-ATPase.