Molecular Cloning of Ca2+/Calmodulin-Dependent Protein Kinase Phosphatase

Kitani, Takako; Ishida, Atsuhiko; Okuno, Sachiko; Takeuchi, Masayuki; Kameshita, Isamu; Fujisawa, Hitoshi

doi:10.1093/oxfordjournals.jbchem.a022381

Cited by 49 publications

(53 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since then, two groups of investigators have independently isolated the same cDNA from different sources and have named it hFEM-2 (30) and POPX2 (31), depending on its identified function. Both groups recognized what we had found earlier during the course of our investigation, 2 the human sequence shares 80% identity with the rat Ca 2ϩ /calmodulin-dependent protein kinase phosphatase (rCaMKPase) (32); however, neither group fully investigated this possible function of the gene, other than to demonstrate that a partially purified hFEM-2 could dephosphorylate CaMKII in vitro (30). The rCaMKPase has characteristics similar to members of the PP2C family, including a dependence on divalent cations for activity and insensitivity to okadaic acid (OA), and has been shown to dephosphorylate as well as deactivate autophosphorylated CaMKII in vitro (33).…”

supporting

confidence: 82%

See 1 more Smart Citation

Regulation of the Multifunctional Ca2+/Calmodulin-dependent Protein Kinase II by the PP2C Phosphatase PPM1F in Fibroblasts

Harvey¹,

Banga

Ozer

2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

The regulation of the multifunctional calcium/calmodulin dependent protein kinase II (CaMKII) by serine/ threonine protein phosphatases has been extensively studied in neuronal cells; however, this regulation has not been investigated previously in fibroblasts. We cloned a cDNA from SV40-transformed human fibroblasts that shares 80% homology to a rat calcium/calmodulin-dependent protein kinase phosphatase that encodes a PPM1F protein. By using extracts from transfected cells, PPM1F, but not a mutant (R326A) in the conserved catalytic domain, was found to dephosphorylate in vitro a peptide corresponding to the autoinhibitory region of CaMKII. Further analyses demonstrated that PPM1F specifically dephosphorylates the phospho-Thr-286 in autophosphorylated CaMKII substrate and thus deactivates the CaMKII in vitro. Coimmunoprecipitation of CaMKII with PPM1F indicates that the two proteins can interact intracellularly. Binding of PPM1F to CaMKII involves multiple regions and is not dependent on intact phosphatase activity. Furthermore, overexpression of PPM1F in fibroblasts caused a reduction in the CaMKII-specific phosphorylation of the known substrate vimentin(Ser-82) following induction of the endogenous CaM kinase. These results identify PPM1F as a CaM kinase phosphatase within fibroblasts, although it may have additional functions intracellularly since it has been presented elsewhere as POPX2 and hFEM-2. We conclude that PPM1F, possibly together with the other previously described protein phosphatases PP1 and PP2A, can regulate the activity of CaMKII. Moreover, because PPM1F dephosphorylates the critical autophosphorylation site of CaMKII, we propose that this phosphatase plays a key role in the regulation of the kinase intracellularly.The dynamic interactions between kinases and phosphatases play a critical role in the regulation of cellular processes. Because of their extensive involvement in calcium signaling (1), the multifunctional Ca 2ϩ /calmodulin-dependent protein kinase II (CaMKII) 1 and the protein phosphatases that interact with it have been the focus of several studies. In response to Ca 2ϩ -mobilizing agents, CaMKII is autophosphorylated (at Thr-286 for CaMKII␣) generating a kinase with Ca 2ϩ -independent activity (autonomous activity); however, this activity rapidly declines on removal of the stimulus (2-4), suggesting that protein phosphatases may contribute to the regulation of CaM kinase. Dephosphorylation of Thr-286 by the serine/threonine protein phosphatases PP1 (5), PP2A (6), and PP2C (7) has been shown to occur in vitro, and the phosphatase(s) responsible for regulating the endogenous CaMKII activity have been identified in a variety of cell types (7-15).Because CaMKII comprises up to 2% of the total protein in some regions of the brain, multiple investigations into the regulation of this kinase by phosphatases have been done with tissue from the central nervous system (7-12, 15). In the rat forebrain, the predominant phosphatase varies with the distinct cellular compartment; PP2A dephosphor...

show abstract

supporting

confidence: 82%

“…While these studies were ongoing, the putative PPM1F-A sequence was found to share 80% identity with rCaMKPase (32), suggesting that PPM1F could act as a CaM kinase phosphatase. The rCaMKPase has been shown to dephosphorylate specifically and to deactivate CaMKI, -II, and -IV (45).…”

Section: Clone J4-3 As a Potential Cam Kinase Phosphatase-j4-3mentioning

confidence: 99%

Regulation of the Multifunctional Ca2+/Calmodulin-dependent Protein Kinase II by the PP2C Phosphatase PPM1F in Fibroblasts

Harvey¹,

Banga

Ozer

2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…In forebrain extracts, PP1 and PP2A account for the majority of phosphatase activity measured using Thr 286 -autophosphorylated CaMKII (see below) (Strack et al, 1997a). Although PP2C may make only a small contribution to CaMKII dephosphorylation in forebrain (Strack et al, 1997a), it may have more significant roles in cerebellum and other cells (Fukunaga et al, 1993;Ishida et al, 1998;Kitani et al, 1999 (Patton et al, 1990;Fukunaga et al, 1993). Although specific phosphatase complexes involved in CaMKII dephosphorylation have not been identified, a novel aspect of CaMKII regulation is that the physiologically relevant phosphatase appears to depend on the subcellular localization of the kinase.…”

Section: Pp2b Complexesmentioning

confidence: 99%

Protein Phosphatases and Calcium/Calmodulin-Dependent Protein Kinase II-Dependent Synaptic Plasticity: Figure 1.

Colbran¹

2004

J. Neurosci.

129

104

View full text Add to dashboard Cite

“…Ca 2+ /calmodulin-dependent protein kinase phosphatase (CaMKP) and its nuclear homolog CaMKP-N are unique protein phosphatases that specifically dephosphorylate and regulate multifunctional CaMKs such as CaMKI, II, and IV [5][6][7][8][9]. CaMKP and CaMKP-N are Mn 2+ -dependent, calyculin A/okadaic acid-insensitive Ser/Thr protein phosphatases that belong to the PPM family and share 28% homology with the catalytic domain of protein phosphatase 2C (PP2C) α [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…CaMKP and CaMKP-N are Mn 2+ -dependent, calyculin A/okadaic acid-insensitive Ser/Thr protein phosphatases that belong to the PPM family and share 28% homology with the catalytic domain of protein phosphatase 2C (PP2C) α [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Inhibitors of the Ca2+/calmodulin-dependent protein kinase phosphatase family (CaMKP and CaMKP-N)

Sueyoshi

Takao

Nimura

et al. 2007

Biochemical and Biophysical Research Communications

View full text Add to dashboard Cite

multifunctional CaMKI, II, and IV. However, the lack of specific inhibitors of these phosphatases has hampered studies on these enzymes in vivo. In an attempt to obtain specific inhibitors, we searched inhibitory compounds and found that Evans Blue and Chicago Sky Blue 6B served as effective inhibitors for CaMKP. These compounds also inhibited CaMKP-N, but inhibited neither protein phosphatase 2C, another member of PPM family phosphatase, nor calcineurin, a typical PPP family phosphatase. The minimum structure required for the inhibition was 1-amino-8-naphthol-4-sulfonic acid.When Neuro2a cells cotransfected with CaMKIV and CaMKP-N were treated with these compounds, the dephosphorylation of CaMKIV was strongly suppressed, suggesting that these compounds could be used as potent inhibitors of CaMKP and CaMKP-N in vivo as well as in vitro.

show abstract

Molecular Cloning of Ca2+/Calmodulin-Dependent Protein Kinase Phosphatase

Cited by 49 publications

References 0 publications

Regulation of the Multifunctional Ca2+/Calmodulin-dependent Protein Kinase II by the PP2C Phosphatase PPM1F in Fibroblasts

Regulation of the Multifunctional Ca2+/Calmodulin-dependent Protein Kinase II by the PP2C Phosphatase PPM1F in Fibroblasts

Protein Phosphatases and Calcium/Calmodulin-Dependent Protein Kinase II-Dependent Synaptic Plasticity: Figure 1.

Inhibitors of the Ca2+/calmodulin-dependent protein kinase phosphatase family (CaMKP and CaMKP-N)

Contact Info

Product

Resources

About