ArticleProceedings of the National Academy of Sciences of the United States of America2004
Phosphoprotein inhibitor CPI-17 specificity depends on allosteric regulation of protein phosphatase-1 by regulatory subunits.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2004. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 43 papers.
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Who cites it
43 citing papers in PubMed, 96 citations in OpenAlex.
- The nitrogen starvation-induced inhibitor Rts3 restrains Sit4/PP6 to gate quiescence downstream of TORC1.Nature communications · 2026Article
- LIMK2-1 Is a Phosphorylation-Dependent Inhibitor of Protein Phosphatase-1 Catalytic Subunit and Myosin Phosphatase Holoenzyme.International journal of molecular sciences · 2025Article
- Serine/Threonine Protein Phosphatases 1 and 2A in Lung Endothelial Barrier Regulation.Biomedicines · 2023Review
- Article
- Possible roles of N- and C-terminal unstructured tails of CPI-17 in regulating CaJournal of smooth muscle research = Nihon Heikatsukin Gakkai kikanshi · 2022Article
- Article
- The Evolution of Duplicated Genes of the Cpi-17/Phi-1 (International journal of molecular sciences · 2020Article
- TIMAP inhibits endothelial myosin light chain phosphatase by competing with MYPT1 for the catalytic protein phosphatase 1 subunit PP1cβ.The Journal of biological chemistry · 2019Article
- Promoter methylation changes and vascular dysfunction in pre-eclamptic umbilical vein.Clinical epigenetics · 2019Article
- Expression And Biological Interaction Network Of RHOC For Hepatic Carcinoma With Metastasis In PBMC Samples.OncoTargets and therapy · 2019Article
- Induction of myosin light chain kinase and CPI-17 by TGF-β accelerates contractile activity in intestinal epithelial cells.The Journal of veterinary medical science · 2018Article
- Protein phosphatases 1 and 2A and their naturally occurring inhibitors: current topics in smooth muscle physiology and chemical biology.The journal of physiological sciences : JPS · 2018Review
- Expression of MYPT1, CPI-17 and MLC20 in ileum of neonatal mouse NEC model and its significance.Experimental and therapeutic medicine · 2017Article
- Unfair competition governs the interaction of pCPI-17 with myosin phosphatase (PP1-MYPT1).eLife · 2017Article
- Diversity and plasticity in signaling pathways that regulate smooth muscle responsiveness: Paradigms and paradoxes for the myosin phosphatase, the master regulator of smooth muscle contraction.Journal of smooth muscle research = Nihon Heikatsukin Gakkai kikanshi · 2017Review
- Calcium Sensitization Mechanisms in Gastrointestinal Smooth Muscles.Journal of neurogastroenterology and motility · 2016Review
- Calcium desensitisation in late polymicrobial sepsis is associated with loss of vasopressor sensitivity in a murine model.Intensive care medicine experimental · 2015Article
- In vivo roles for myosin phosphatase targeting subunit-1 phosphorylation sites T694 and T852 in bladder smooth muscle contraction.The Journal of physiology · 2015Article
- Myosin phosphatase target subunit 1 (MYPT1) regulates the contraction and relaxation of vascular smooth muscle and maintains blood pressure.The Journal of biological chemistry · 2014Article
- Reconstituted human myosin light chain phosphatase reveals distinct roles of two inhibitory phosphorylation sites of the regulatory subunit, MYPT1.Biochemistry · 2014Article
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Authors and funding
3 authors at 2 institutions in 1 country.
Funding
Abstract
Inhibition of myosin phosphatase is critical for agonist-induced contractility of vascular smooth muscle. The protein CPI-17 is a phosphorylation-dependent inhibitor of myosin phosphatase and, in response to agonists, Thr-38 is phosphorylated by protein kinase C, producing a >1,000-fold increase in inhibitory potency. Here, we addressed how CPI-17 could selectively inhibit myosin phosphatase among other protein phosphatase-1 (PP1) holoenzymes. PP1 in cell lysates was separated by sequential affinity chromatography into at least two fractions, one bound specifically to thiophospho-CPI-17, and another bound specifically to inhibitor-2. The MYPT1 regulatory subunit of myosin phosphatase was concentrated only in the fraction bound to thiophospho-CPI-17. This binding was eliminated by addition of excess microcystin-LR to the lysate, showing that binding at the active site of PP1 is required. Phospho-CPI-17 failed to inhibit glycogen-bound PP1 from skeletal muscle, composed primarily of PP1 with the striated muscle glycogen-targeting subunit (G(M)) regulatory subunit. Phospho-CPI-17 was dephosphorylated during assay of glycogen-bound PP1, not MYPT1-associated PP1, even though these two holoenzymes have the same PP1 catalytic subunit. Phosphorylation of CPI-17 in rabbit arteries was enhanced by calyculin A but not okadaic acid or fostriecin, consistent with PP1-mediated dephosphorylation. We propose that CPI-17 binds at the PP1 active site where it is dephosphorylated, but association of MYPT1 with PP1C allosterically retards this hydrolysis, resulting in formation of a complex of MYPT1.PP1C.P-CPI-17, leading to an increase in smooth muscle contraction.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.