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Sul1 and Sul2 sulfate transceptors signal to protein kinase A upon exit of sulfur starvation.

Kankipati HN, Rubio-Texeira M, Castermans D, Diallinas G, Thevelein JM - J. Biol. Chem. (2015)

Bottom Line: Overall, our data suggest that transceptors can undergo independent conformational changes, each responsible for triggering different downstream processes.The Sul1 and Sul2 transceptors are the first identified plasma membrane sensors for extracellular sulfate.High affinity transporters induced upon starvation for their substrate may generally act as transceptors during exit from starvation.

View Article: PubMed Central - PubMed

Affiliation: From the Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, the Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, and.

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Sulfate transport and sulfate-induced PKA signaling in cells expressing Sul1 and Sul2 versions mutated in different putative proton-binding residues.A, uptake rate of 0.1 mm [35S]sulfate in sulfur-starved cells expressing wild type Sul1-HA, Sul2-HA, or a mutant form. B, trehalase activation upon the addition of 3 mm sulfate to sulfur-starved cells expressing the following: Sul1-HA (●), Sul1D124N-HA (○), Sul1D483N-HA (▴), Sul1E538Q-HA (▵), and Sul1E427Q-HA (■) (left) and Sul2-HA (●), Sul2D305N-HA (○), Sul2D519N-HA (▴), and Sul2E443Q-HA (▵) (right). Error bars, S.D.
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Figure 6: Sulfate transport and sulfate-induced PKA signaling in cells expressing Sul1 and Sul2 versions mutated in different putative proton-binding residues.A, uptake rate of 0.1 mm [35S]sulfate in sulfur-starved cells expressing wild type Sul1-HA, Sul2-HA, or a mutant form. B, trehalase activation upon the addition of 3 mm sulfate to sulfur-starved cells expressing the following: Sul1-HA (●), Sul1D124N-HA (○), Sul1D483N-HA (▴), Sul1E538Q-HA (▵), and Sul1E427Q-HA (■) (left) and Sul2-HA (●), Sul2D305N-HA (○), Sul2D519N-HA (▴), and Sul2E443Q-HA (▵) (right). Error bars, S.D.

Mentions: Glu and Asp residues were individually mutagenized to uncharged Gln and Asn residues, respectively. Plasmids encoding C-terminally HA-tagged versions of Sul1 and Sul2 containing the respective mutation (Sul1mut-HA or Sul2mut-HA) were constructed, transformed in the sul1Δ sul2Δ strain, and tested for proper expression of the mutant proteins by Western blot analysis of membrane-enriched (P13) protein extracts (Fig. 5B). Strains expressing these proteins were then investigated for their sulfate transport and signaling activities in sulfur-starved cells and compared with a strain expressing the wild type construct. The sulfate uptake rate with different mutant forms of Sul1 and Sul2 was significantly reduced (Figs. 5 (C and D) and 6A). Sul1E427Q-HA, Sul1D124N-HA, and Sul2E443Q-HA showed negligible uptake activity (Figs. 5 (C and D) and 6A) despite being properly expressed as assessed by Western blot analysis of the HA-tagged versions present in membrane-enriched fractions of sulfur-starved cells (Fig. 5B).


Sul1 and Sul2 sulfate transceptors signal to protein kinase A upon exit of sulfur starvation.

Kankipati HN, Rubio-Texeira M, Castermans D, Diallinas G, Thevelein JM - J. Biol. Chem. (2015)

Sulfate transport and sulfate-induced PKA signaling in cells expressing Sul1 and Sul2 versions mutated in different putative proton-binding residues.A, uptake rate of 0.1 mm [35S]sulfate in sulfur-starved cells expressing wild type Sul1-HA, Sul2-HA, or a mutant form. B, trehalase activation upon the addition of 3 mm sulfate to sulfur-starved cells expressing the following: Sul1-HA (●), Sul1D124N-HA (○), Sul1D483N-HA (▴), Sul1E538Q-HA (▵), and Sul1E427Q-HA (■) (left) and Sul2-HA (●), Sul2D305N-HA (○), Sul2D519N-HA (▴), and Sul2E443Q-HA (▵) (right). Error bars, S.D.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4400352&req=5

Figure 6: Sulfate transport and sulfate-induced PKA signaling in cells expressing Sul1 and Sul2 versions mutated in different putative proton-binding residues.A, uptake rate of 0.1 mm [35S]sulfate in sulfur-starved cells expressing wild type Sul1-HA, Sul2-HA, or a mutant form. B, trehalase activation upon the addition of 3 mm sulfate to sulfur-starved cells expressing the following: Sul1-HA (●), Sul1D124N-HA (○), Sul1D483N-HA (▴), Sul1E538Q-HA (▵), and Sul1E427Q-HA (■) (left) and Sul2-HA (●), Sul2D305N-HA (○), Sul2D519N-HA (▴), and Sul2E443Q-HA (▵) (right). Error bars, S.D.
Mentions: Glu and Asp residues were individually mutagenized to uncharged Gln and Asn residues, respectively. Plasmids encoding C-terminally HA-tagged versions of Sul1 and Sul2 containing the respective mutation (Sul1mut-HA or Sul2mut-HA) were constructed, transformed in the sul1Δ sul2Δ strain, and tested for proper expression of the mutant proteins by Western blot analysis of membrane-enriched (P13) protein extracts (Fig. 5B). Strains expressing these proteins were then investigated for their sulfate transport and signaling activities in sulfur-starved cells and compared with a strain expressing the wild type construct. The sulfate uptake rate with different mutant forms of Sul1 and Sul2 was significantly reduced (Figs. 5 (C and D) and 6A). Sul1E427Q-HA, Sul1D124N-HA, and Sul2E443Q-HA showed negligible uptake activity (Figs. 5 (C and D) and 6A) despite being properly expressed as assessed by Western blot analysis of the HA-tagged versions present in membrane-enriched fractions of sulfur-starved cells (Fig. 5B).

Bottom Line: Overall, our data suggest that transceptors can undergo independent conformational changes, each responsible for triggering different downstream processes.The Sul1 and Sul2 transceptors are the first identified plasma membrane sensors for extracellular sulfate.High affinity transporters induced upon starvation for their substrate may generally act as transceptors during exit from starvation.

View Article: PubMed Central - PubMed

Affiliation: From the Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, the Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, and.

Show MeSH
Related in: MedlinePlus