lnu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Ruiz-Pavon, Lorena
Publications (7 of 7) Show all publications
Sengottaiyan, P., Petrlova, J., Lagerstedt, J., Ruiz-Pavon, L., Budamagunta, M., Voss, J. & Persson, B. L. (2013). Characterization of the biochemical and biophysical properties of the Saccharomyces cerevisiae phosphate transporter Pho89. Biochemical and Biophysical Research Communications - BBRC, 436(3), 551-556
Open this publication in new window or tab >>Characterization of the biochemical and biophysical properties of the Saccharomyces cerevisiae phosphate transporter Pho89
Show others...
2013 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 436, no 3, p. 551-556Article in journal (Refereed) Published
Abstract [en]

In Saccharomyces cerevisiae, Pho89 mediates a cation-dependent transport of Pi across the plasma membrane. This integral membrane protein belongs to the Inorganic Phosphate Transporter (PiT) family, a group that includes the mammalian Na+/Pi cotransporters Pit1 and Pit2. Here we report that the Pichia pastoris expressed recombinant Pho89 was purified in the presence of Foscholine-12 and functionally reconstituted into proteoliposomes with a similar substrate specificity as observed in an intact cell system. The alpha-helical content of the Pho89 protein was estimated to 44%. EPR analysis showed that purified Pho89 protein undergoes conformational change upon addition of substrate. 

Place, publisher, year, edition, pages
Elsevier, 2013
Keywords
Pho89, Pichia pastoris, Oligomer, Reconstitution, Phosphate transport, Circular dichroism
National Category
Chemical Sciences Biochemistry and Molecular Biology
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-27720 (URN)10.1016/j.bbrc.2013.06.011 (DOI)000321995900034 ()2-s2.0-84879889835 (Scopus ID)
Projects
Characterization of sensors and signal transduction in regulation of phosphate uptake systems
Funder
Swedish Research Council, 621-2007-6144Swedish Research Council, 522-2008-3724,7480
Available from: 2013-08-01 Created: 2013-08-01 Last updated: 2018-11-16Bibliographically approved
Sengottaiyan, P., Ruiz-Pavon, L. & Persson, B. L. (2013). Functional expression, purification and reconstitution of the recombinant phosphate transporter Pho89 of Saccharomyces cerevisiae. The FEBS Journal, 280(3), 965-975
Open this publication in new window or tab >>Functional expression, purification and reconstitution of the recombinant phosphate transporter Pho89 of Saccharomyces cerevisiae
2013 (English)In: The FEBS Journal, ISSN 1742-464X, E-ISSN 1742-4658, Vol. 280, no 3, p. 965-975Article in journal (Refereed) Published
Abstract [en]

The Saccharomyces cerevisiae high-affinity phosphate transporter Pho89 is a member of the inorganic phosphate (Pi) transporter (PiT) family, and shares significant homology with the type III Na+/Pi symporters, hPit1 and hPit2. Currently, detailed biochemical and biophysical analyses of Pho89 to better understand its transport mechanisms are limited, owing to the lack of purified Pho89 in an active form. In the present study, we expressed functional Pho89 in the cell membrane of Pichia pastoris, solubilized it in Triton X-100 and foscholine-12, and purified it by immobilized nickel affinity chromatography combined with size exclusion chromatography. The protein eluted as an oligomer on the gel filtration column, and SDS/PAGE followed by western blotting analysis revealed that the protein appeared as bands of approximately 63, 140 and 520 kDa, corresponding to the monomeric, dimeric and oligomeric masses of the protein, respec- tively. Proteoliposomes containing purified and reconstituted Pho89 showed Na+-dependent Pi transport activity driven by an artificially imposed electrochemical Na+ gradient. This implies that Pho89 operates as a symporter. Moreover, its activity is sensitive to the Na+ ionophore monensin. To our knowledge, this study represents the first report on the functional reconstitution of a Pi-coupled PiT family member. 

Place, publisher, year, edition, pages
Wiley-Blackwell, 2013
Keywords
Pho89, phosphate transport reconstitution, Pichia pastoris, Saccharomyces cerevisiae
National Category
Biochemistry and Molecular Biology
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-23435 (URN)10.1111/febs.12090 (DOI)000314167100015 ()23216645 (PubMedID)2-s2.0-84873160670 (Scopus ID)
Projects
Karakterisering av sensorer och signalöverföring i reglering av cellulära fosfatupptagssystem
Funder
Swedish Research Council, 621-2007-6144
Available from: 2013-01-22 Created: 2013-01-14 Last updated: 2017-12-06Bibliographically approved
Samyn, D. R., Andersson, M., Ruiz-Pavon, L., Popova, Y., Persson, B. L. & Thevelein, J. (2013). The high-affinity inorganic phosphate transport system of Saccharomyces cerevisiae: a tale of two proteins. Paper presented at 38th Congress of the Federation-of-European-Biochemical-Societies (FEBS), JUL 06-11, 2013, Saint Petersburg, RUSSIA. The FEBS Journal, 280, 152-152
Open this publication in new window or tab >>The high-affinity inorganic phosphate transport system of Saccharomyces cerevisiae: a tale of two proteins
Show others...
2013 (English)In: The FEBS Journal, ISSN 1742-464X, E-ISSN 1742-4658, Vol. 280, p. 152-152Article in journal, Meeting abstract (Other academic) Published
National Category
Biochemistry and Molecular Biology
Research subject
Natural Science, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-31011 (URN)000325919200473 ()
Conference
38th Congress of the Federation-of-European-Biochemical-Societies (FEBS), JUL 06-11, 2013, Saint Petersburg, RUSSIA
Available from: 2013-12-09 Created: 2013-12-06 Last updated: 2017-12-06Bibliographically approved
Samyn, D. R., Ruiz-Pavon, L., Andersson, M. R., Popova, Y., Thevelein, J. & Persson, B. L. (2012). Mutational analysis of putative phosphate- and proton-binding sites in the Saccharomyces cerevisiae Pho84 phosphate:H+ transceptor and its effect on signalling to the PKA and PHO pathways. Biochemical Journal, 445, 413-422
Open this publication in new window or tab >>Mutational analysis of putative phosphate- and proton-binding sites in the Saccharomyces cerevisiae Pho84 phosphate:H+ transceptor and its effect on signalling to the PKA and PHO pathways
Show others...
2012 (English)In: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 445, p. 413-422Article in journal (Refereed) Published
Abstract [en]

In Saccharomyces cerevisiae, the Pho84 phosphate transporter acts as the main provider of phosphate to the cell using a proton symport mechanism, but also mediates rapid activation of the PKA (protein kinase A) pathway. These two features led to recognition of Pho84 as a transceptor. Although the physiological role of Pho84 has been studied in depth, the mechanisms underlying the transport and sensor functions are unclear. To obtain more insight into the structure–function relationships of Pho84, we have rationally designed and analysed site-directed mutants. Using a three-dimensional model of Pho84 created on the basis of the GlpT permease, complemented with multiple sequence alignments, we selected Arg168 and Lys492, and Asp178, Asp358 and Glu473 as residues potentially involved in phosphate or proton binding respectively, during transport. We found that Asp358 (helix 7) and Lys492 (helix 11) are critical for the transport function, and might be part of the putative substrate-binding pocket of Pho84. Moreover, we show that alleles mutated in the putative proton-binding site Asp358 are still capable of strongly activating PKA pathway targets, despite their severely reduced transport activity. This indicates that signalling does not require transport and suggests that mutagenesis of amino acid residues involved in binding of the co-transported ion may constitute a promising general approach to separate the transport and signalling functions in transceptors.

Place, publisher, year, edition, pages
Portland Press, 2012
Keywords
Pho84, phosphate binding, phosphate transport, protein kinase A, proton binding, Saccharomyces cerevisiae, transceptor.
National Category
Biochemistry and Molecular Biology
Research subject
Natural Science, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-20897 (URN)10.1042/BJ20112086 (DOI)2-s2.0-84864360049 (Scopus ID)
Projects
Characterization of sensors and signal transduction in regulation of phosphate uptake systems
Funder
Swedish Research Council, 621-2007-6144
Available from: 2012-07-27 Created: 2012-07-27 Last updated: 2017-12-07Bibliographically approved
Sengottaiyan, P., Spetea, C., Lagerstedt, J. O., Samyn, D. R., Andersson, M. R., Ruiz-Pavon, L. & Persson, B. L. (2012). The intrinsic GTPase activity of the Gtr1 protein from Saccharomyces cerevisiae. BMC Biochemistry, 13, Article ID 11.
Open this publication in new window or tab >>The intrinsic GTPase activity of the Gtr1 protein from Saccharomyces cerevisiae
Show others...
2012 (English)In: BMC Biochemistry, ISSN 1471-2091, E-ISSN 1471-2091, Vol. 13, article id 11Article in journal (Refereed) Published
Abstract [en]

Background

The Gtr1 protein of Saccharomyces cerevisiae is a member of the RagA subfamily of the Ras-like small GTPase superfamily. Gtr1 has been implicated in various cellular processes. Particularly, the Switch regions in the GTPase domain of Gtr1 are essential for TORC1 activation and amino acid signaling [R. Gong, L. Li, Y. Liu, P. Wang, H. Yang, L. Wang, J. Cheng, K.L. Guan, Y. Xu, Genes Dev. 25 (2011) 1668–1673]. Therefore, knowledge about the biochemical activity of Gtr1 is required to understand its mode of action and regulation.

Results

By employing tryptophan fluorescence analysis and radioactive GTPase assays, we demonstrate that Gtr1 can adopt two distinct GDP- and GTP-bound conformations, and that it hydrolyses GTP much slower than Ras proteins. Using cysteine mutagenesis of Arginine-37 and Valine-67, residues at the Switch I and II regions, respectively, we show altered GTPase activity and associated conformational changes as compared to the wild type protein and the cysteine-less mutant.

Conclusions

The extremely low intrinsic GTPase activity of Gtr1 implies requirement for interaction with activating proteins to support its physiological function. These findings as well as the altered properties obtained by mutagenesis in the Switch regions provide insights into the function of Gtr1 and its homologues in yeast and mammals.

Place, publisher, year, edition, pages
BioMed Central, 2012
Keywords
Gtr1, GTPase, Intrinsic tryptophan fluorescence, Rag GTPase, Cysteine mutagenesis, Switch region
National Category
Biochemistry and Molecular Biology
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-20450 (URN)10.1186/1471-2091-13-11 (DOI)2-s2.0-84862569403 (Scopus ID)
Projects
Phosphate sensing and signaling in yeast
Funder
Swedish Research Council, 621-2003-3558 and 621-2007-6144
Available from: 2012-06-25 Created: 2012-06-25 Last updated: 2017-12-07Bibliographically approved
Ruiz-Pavon, L., Karlsson, P. M., Carlsson, J., Samyn, D. R., Persson, B. L., Persson, B. L. & Spetea, C. (2010). Functionally important amino acids in the Arabidopsis thylakoid phosphate transporter: Homology modeling and site-directed mutagenesis. Biochemistry, 49(30), 6430-6439
Open this publication in new window or tab >>Functionally important amino acids in the Arabidopsis thylakoid phosphate transporter: Homology modeling and site-directed mutagenesis
Show others...
2010 (English)In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 49, no 30, p. 6430-6439Article in journal (Refereed) Published
Abstract [en]

The anion transporter 1 (ANTR1) from Arabidopsis thaliana, homologous to the mammalian members of the solute carrier 17 (SLC17) family, is located in the chloroplast thylakoid membrane. When expressed heterologously in Escherichia coli, ANTR1 mediates a Na+-dependent active transport of inorganic phosphate (Pi). The aim of this study was to identify amino acid residues involved in Pi binding and translocation by ANTR1 and in the Na+ dependence of its activity. A three-dimensional structural model of ANTR1 was constructed using the crystal structure of glycerol 3-phosphate/phosphate antiporter from E. coli as a template. Based on this model and multiple sequence alignments, five highly conserved residues in plant ANTRs and mammalian SLC17 homologues have been selected for site-directed mutagenesis, namely, Arg-120, Ser-124, and Arg-201 inside the putative translocation pathway and Arg-228 and Asp-382 exposed at the cytoplasmic surface of the protein. The activities of the wild-type and mutant proteins have been analyzed using expression in E. coli and radioactive Pi transport assays and compared with bacterial cells carrying an empty plasmid. The results from Pi- and Na+-dependent kinetics indicate the following: (i) Arg-120 and Arg-201 may be important for binding and translocation of the substrate; (ii) Ser-124 may function as a transient binding site for Na+ ions in close proximity to the periplasmic side; (iii) Arg-228 and Asp-382 may participate in interactions associated with protein conformational changes required for full transport activity. Functional characterization of ANTR1 should provide useful insights into the function of other plant and mammalian SLC17 homologous transporters.

Place, publisher, year, edition, pages
American Chemical Society, 2010
Keywords
Antr1, phosphate transport, Arabidopsis, Major facilitator superfamily, Escherichia coli, Lactose permease, Inorganic-phosphate, transmembrane topology, Membrane-proteins, Crystal structure, Envelope, Family, Cotransporter
National Category
Biochemistry and Molecular Biology
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-6914 (URN)10.1021/bi100239j (DOI)2-s2.0-77955043211 (Scopus ID)
External cooperation:
Projects
Characterization of sensors and signal transduction in regulation of phosphate uptake systems.
Funder
Swedish Research Council, 621-2007-6144
Available from: 2010-07-30 Created: 2010-07-30 Last updated: 2017-12-12Bibliographically approved
Ruiz-Pavon, L., Lundh, F., Lundin, B., Mishra, A., Persson, B. L. & Spetea, C. (2008). Arabidopsis ANTR1 is a thylakoid Na+-dependent phosphate transporter - Functional characterization in Escherichia coli.. Journal of Biological Chemistry, 283(20), 13520-13527
Open this publication in new window or tab >>Arabidopsis ANTR1 is a thylakoid Na+-dependent phosphate transporter - Functional characterization in Escherichia coli.
Show others...
2008 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 283, no 20, p. 13520-13527Article in journal (Refereed) Published
National Category
Natural Sciences
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-1701 (URN)
External cooperation:
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-12-12Bibliographically approved

Search in DiVA

Show all publications