Regulatory Subunit Myristoylation Antagonizes Calcineurin Phosphatase Activation in Yeast |
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Authors: | Sean Connolly Tami Kingsbury |
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Institution: | From the Department of Physiology, Center for Stem Cell Biology and Regenerative Medicine, Program in Oncology, Marlene and Stewart Greenbaum Cancer Center, the University of Maryland Baltimore School of Medicine, Baltimore, Maryland 21201 |
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Abstract: | The Ca2+/calmodulin-stimulated protein phosphatase calcineurin is a critical component of Ca2+ signaling cascades in eukaryotic cells. Myristoylation of the regulatory subunit of calcineurin (CNB) is conserved from yeast to humans. Here, we show that CNB myristoylation antagonizes phosphatase activation in yeast. Disruption of CNB myristoylation by mutation of the myristoylated glycine triggered constitutive expression of a calcineurin-dependent reporter gene and enhanced calcineurin-dependent phenotypes. Basal phosphatase activity was also increased in nmt1–181 yeast with reduced N-myristoyltransferase activity. Our findings are the first demonstration of a functional role for CNB myristoylation and reveal the importance of Nmt1 in modulating cellular calcineurin activation. |
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Keywords: | Calcineurin Calcium Signaling Cell Signaling Protein Myristoylation Protein Phosphatase Crz1 N-Myristoyltransferase |
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