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Calcineurin regulates the yeast synaptojanin Inp53/Sjl3 during membrane stress.

Guiney EL, Goldman AR, Elias JE, Cyert MS - Mol. Biol. Cell (2014)

Bottom Line: By activating Inp53, calcineurin repolarizes the actin cytoskeleton and maintains normal plasma membrane morphology in synaptojanin-limited cells.This response has physiological and molecular similarities to calcineurin-regulated activity-dependent bulk endocytosis in neurons, which retrieves a bolus of plasma membrane deposited by synaptic vesicle fusion.We propose that activation of Ca(2+)/calcineurin and PI(4,5)P2 signaling to regulate endocytosis is a fundamental and conserved response to excess membrane in eukaryotic cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Stanford University, Stanford, CA 94305.

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Calcineurin-activated gene expression is inhibited during hyperosmotic shock. Ca2+/CN–dependent Crz1 transcription was measured with a CDRE-LacZ reporter. β-Galactosidase activity normalized to protein concentration is reported. Cells were treated for 90 min with 200 mM CaCl2 and/or 1.25 M KCl as indicated. Error bars are SD; ***p < 0.001.
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Figure 2: Calcineurin-activated gene expression is inhibited during hyperosmotic shock. Ca2+/CN–dependent Crz1 transcription was measured with a CDRE-LacZ reporter. β-Galactosidase activity normalized to protein concentration is reported. Cells were treated for 90 min with 200 mM CaCl2 and/or 1.25 M KCl as indicated. Error bars are SD; ***p < 0.001.

Mentions: Under many environmental conditions, CN ensures cell survival by activating the Crz1 transcription factor, promoting its translocation from the cytosol to the nucleus (Stathopoulos and Cyert, 1997; Stathopoulos-Gerontides et al., 1999). Therefore we measured CN-Crz1–dependent expression of 4x-CDRE-LacZ, a reporter gene controlled by the Crz1- binding site, during hyperosmotic stress. As expected, addition of CaCl2 caused a 40-fold induction of CDRE-LacZ expression (Figure 2). In contrast, no activation of CN-Crz1 signaling was observed in response to hyperosmotic stress despite the increase in intracellular Ca2+ that occurs under these conditions (Denis and Cyert, 2002). Instead, hyperosmotic stress blocked Ca2+-dependent activation of Crz1 (Figure 2). This surprising effect suggested that hypertonic conditions inhibit CN/Crz1 signaling, perhaps in part by relocalizing CN and preventing its access to Crz1.


Calcineurin regulates the yeast synaptojanin Inp53/Sjl3 during membrane stress.

Guiney EL, Goldman AR, Elias JE, Cyert MS - Mol. Biol. Cell (2014)

Calcineurin-activated gene expression is inhibited during hyperosmotic shock. Ca2+/CN–dependent Crz1 transcription was measured with a CDRE-LacZ reporter. β-Galactosidase activity normalized to protein concentration is reported. Cells were treated for 90 min with 200 mM CaCl2 and/or 1.25 M KCl as indicated. Error bars are SD; ***p < 0.001.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4325846&req=5

Figure 2: Calcineurin-activated gene expression is inhibited during hyperosmotic shock. Ca2+/CN–dependent Crz1 transcription was measured with a CDRE-LacZ reporter. β-Galactosidase activity normalized to protein concentration is reported. Cells were treated for 90 min with 200 mM CaCl2 and/or 1.25 M KCl as indicated. Error bars are SD; ***p < 0.001.
Mentions: Under many environmental conditions, CN ensures cell survival by activating the Crz1 transcription factor, promoting its translocation from the cytosol to the nucleus (Stathopoulos and Cyert, 1997; Stathopoulos-Gerontides et al., 1999). Therefore we measured CN-Crz1–dependent expression of 4x-CDRE-LacZ, a reporter gene controlled by the Crz1- binding site, during hyperosmotic stress. As expected, addition of CaCl2 caused a 40-fold induction of CDRE-LacZ expression (Figure 2). In contrast, no activation of CN-Crz1 signaling was observed in response to hyperosmotic stress despite the increase in intracellular Ca2+ that occurs under these conditions (Denis and Cyert, 2002). Instead, hyperosmotic stress blocked Ca2+-dependent activation of Crz1 (Figure 2). This surprising effect suggested that hypertonic conditions inhibit CN/Crz1 signaling, perhaps in part by relocalizing CN and preventing its access to Crz1.

Bottom Line: By activating Inp53, calcineurin repolarizes the actin cytoskeleton and maintains normal plasma membrane morphology in synaptojanin-limited cells.This response has physiological and molecular similarities to calcineurin-regulated activity-dependent bulk endocytosis in neurons, which retrieves a bolus of plasma membrane deposited by synaptic vesicle fusion.We propose that activation of Ca(2+)/calcineurin and PI(4,5)P2 signaling to regulate endocytosis is a fundamental and conserved response to excess membrane in eukaryotic cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Stanford University, Stanford, CA 94305.

Show MeSH
Related in: MedlinePlus