Solution NMR structure of the myosin phosphatase inhibitor protein CPI-17 shows phosphorylation-induced conformational changes responsible for activation 1 1Edited by P. E. Wright

Ohki, Shinya; Eto, Masumi; Kariya, Eri; Hayano, Toshiya; Hayashi, Yuichiro; Yazawa, Michio; Brautigan, David L.; Kainosho, Masatsune

doi:10.1006/jmbi.2001.5200

Cited by 37 publications

(25 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The interaction of PP1 and CPI-17 is sensitive to the inhibitor conformation as well, because the Y41A mutant of CPI-17 is dephosphorylated by myosin phosphatase as efficiently as the preferred substrate phospho-myosin light chain (30). The NMR solution structure of CPI-17 reveals an N-terminal loop consisting of the phosphorylation site, called the P-loop, followed by a four-helix bundle (34,35). The Asp mutation at Thr-38, which mimics phosphorylation, exposes the P-loop on the molecular surface (35).…”

Section: Discussionmentioning

confidence: 99%

Phosphoprotein inhibitor CPI-17 specificity depends on allosteric regulation of protein phosphatase-1 by regulatory subunits

Eto

Kitazawa

Brautigan

2004

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

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 glycogentargeting 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 MYPT1⅐PP1C⅐P-CPI-17, leading to an increase in smooth muscle contraction.

show abstract

Section: Discussionmentioning

confidence: 99%

Phosphoprotein inhibitor CPI-17 specificity depends on allosteric regulation of protein phosphatase-1 by regulatory subunits

Eto

Kitazawa

Brautigan

2004

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This lends weight to the hypothesis that phosphorylated CPI-17 binds to PP1 as a pseudosubstrate, that is shielded from dephosphorylation by the side chain of Tyr-41 and to a lesser extent by other adjacent residues. A fragment of CPI-17 encompassing residues 35-120 retains its full inhibitory potency and has been shown to fold into a bundle of four helices, the first of which is reoriented after phosphorylation of the adjacent Thr-38 (285). This fragment is conserved in all other PHIs.…”

Section: The Phismentioning

confidence: 99%

Functional Diversity of Protein Phosphatase-1, a Cellular Economizer and Reset Button

Ceulemans

Bollen

2004

Physiological Reviews

605

584

View full text Add to dashboard Cite

Ceulemans, Hugo, and Mathieu Bollen. Functional Diversity of Protein Phosphatase-1, a Cellular Economizer and Reset Button. Physiol Rev 84: 1–39, 2004; 10.1152/physrev.00013.2003.—The protein serine/threonine phosphatase protein phosphatase-1 (PP1) is a ubiquitous eukaryotic enzyme that regulates a variety of cellular processes through the dephosphorylation of dozens of substrates. This multifunctionality of PP1 relies on its association with a host of function-specific targetting and substrate-specifying proteins. In this review we discuss how PP1 affects the biochemistry and physiology of eukaryotic cells. The picture of PP1 that emerges from this analysis is that of a “green” enzyme that promotes the rational use of energy, the recycling of protein factors, and a reversal of the cell to a basal and/or energy-conserving state. Thus PP1 promotes a shift to the more energy-efficient fuels when nutrients are abundant and stimulates the storage of energy in the form of glycogen. PP1 also enables the relaxation of actomyosin fibers, the return to basal patterns of protein synthesis, and the recycling of transcription and splicing factors. In addition, PP1 plays a key role in the recovery from stress but promotes apoptosis when cells are damaged beyond repair. Furthermore, PP1 downregulates ion pumps and transporters in various tissues and ion channels that are involved in the excitation of neurons. Finally, PP1 promotes the exit from mitosis and maintains cells in the G1or G2phases of the cell cycle.

show abstract

“…Residues 35-120 are required for recognition of MP and Tyr-41 is necessary to reduce dephosphorylation of Thr-38 by MP (39). The solution NMR structure (40) indicates that phosphorylation of Thr-38 induces a conformational change that promotes specific recognition of MP by CPI-17. Histamine stimulation of smooth muscle fibers caused phosphorylation of Thr-38 that was reduced by both ROK and PKC inhibitors, suggesting input from two signaling pathways (41).…”

Section: Regulation Of Mp Activitymentioning

confidence: 99%

Role of Protein Phosphatase Type 1 in Contractile Functions: Myosin Phosphatase

Hartshorne

Erdõdi

2004

Journal of Biological Chemistry

207

219

View full text Add to dashboard Cite

Solution NMR structure of the myosin phosphatase inhibitor protein CPI-17 shows phosphorylation-induced conformational changes responsible for activation 1 1Edited by P. E. Wright

Cited by 37 publications

References 44 publications

Phosphoprotein inhibitor CPI-17 specificity depends on allosteric regulation of protein phosphatase-1 by regulatory subunits

Phosphoprotein inhibitor CPI-17 specificity depends on allosteric regulation of protein phosphatase-1 by regulatory subunits

Functional Diversity of Protein Phosphatase-1, a Cellular Economizer and Reset Button

Role of Protein Phosphatase Type 1 in Contractile Functions: Myosin Phosphatase

Contact Info

Product

Resources

About