Modulation of cofactor requirement for the activation of protein kinase C by heparin Possible effect at the regulatory domain

✓ Vasospasm was produced in adult mongrel dogs by a two-hemorrhage method, and the spastic basilar arteries were exposed via the transclival route on Day 7. Tonic contraction was produced in the normal canine basilar arteries by a local application of KCl or serotonin after transclival exposure. The exposed spastic and tonic basilar arteries then received a topical application of the following: 1-(5-isoquinolinesulfonyl)-2-methyl-piperazine (H-7), a potent inhibitor of protein kinase C acting at the catalytic domain; calphostin C, a specific inhibitor of protein kinase C acting at the regulatory domain; or calpeptin, a selective inhibitor of calpain. Both spastic and tonic basilar arteries were effectively dilated by H-7. Calphostin C caused only slight dilation of spastic basilar arteries but moderate dilation of tonic basilar arteries. Dilation in response to calpeptin was remarkable in the spastic basilar arteries but slight in the tonic basilar arteries. The doses of calphostin C and calpeptin required to obtain maximum effect were markedly lower in the tonic model than in the spastic model. The spastic and tonic models had a similar dose-dependent response to H-7 but quite a different response to calphostin C or calpeptin, suggesting a difference in the function of protein kinase C and calpain in the two models. Furthermore, the effect of calphostin C on the reversal of vasospasm was increased significantly after topical treatment with calpeptin. It is suggested that the majority of the catalytic domain of protein kinase C is dissociated from the regulatory domain, probably by a limited proteolysis with calpain, and is markedly activated in vasospasm.

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The regulatory domain of protein kinase C delta positively regulates insulin receptor signaling

Journal of Molecular Endocrinology ◽

10.1677/jme-09-0119 ◽

2009 ◽

Vol 44 (3) ◽

pp. 155-169 ◽

Cited By ~ 9

Author(s):

Avraham I Jacob ◽

Miriam Horovitz-Fried ◽

Shlomit Aga-Mizrachi ◽

Tamar Brutman-Barazani ◽

Hana Okhrimenko ◽

...

Keyword(s):

Skeletal Muscle ◽

Protein Kinase C ◽

Protein Kinase ◽

Insulin Receptor ◽

Glycogen Synthase ◽

Regulatory Domain ◽

Protein Kinase C Delta ◽

Kinase C ◽

Regulatory Effects ◽

In Cells

Protein kinase C delta (PKCδ) is induced by insulin to rapidly associate with insulin receptor (IR) and upregulates insulin signaling. We utilized specific JM and CT receptor domains and chimeras of PKCα and PKCδ regulatory and catalytic domains to elucidate which components of PKCδ are responsible for positive regulatory effects of PKCδ on IR signaling. Studies were performed on L6 and L8 skeletal muscle myoblasts and myotubes. PKCδ was preferentially bound to the JM domain of IR, and insulin stimulation increased this binding. Both PKCδ/α and PKCα/δ chimeras (regulatory/catalytic) were bound preferentially to the JM but not to the CT domain of IR. Although IR–PKCδ binding was higher in cells expressing either the PKCδ/α or PKCα/δ chimera than in control cells, upregulation of IR signaling was observed only in PKCδ/α cells. Thus, in response to insulin increases in tyrosine phosphorylation of IR and insulin receptor substrate-1, downstream signaling to protein kinase B and glycogen synthase kinase 3 (GSK3) and glucose uptake were greater in cells overexpressing PKCδ/α and the PKCδ/δ domains than in cells expressing the PKCα/δ domains. Basal binding of Src to PKCδ was higher in both PKCδ/α- and PKCα/δ-expressing cells compared to control. Binding of Src to IR was decreased in PKCα/δ cells but remained elevated in the PKCδ/α cells in response to insulin. Finally, insulin increased Src activity in PKCδ/α-expressing cells but decreased it in PKCα/δ-expressing cells. Thus, the regulatory domain of PKCδ via interaction with Src appears to determine the role of PKCδ as a positive regulator of IR signaling in skeletal muscle.

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Protein Kinase C δ (PKCδ) Inhibits the Expression of Glutamine Synthetase in Glial Cells via the PKCδ Regulatory Domain and Its Tyrosine Phosphorylation

Journal of Biological Chemistry ◽

10.1074/jbc.273.46.30713 ◽

1998 ◽

Vol 273 (46) ◽

pp. 30713-30718 ◽

Cited By ~ 29

Author(s):

Chaya Brodie ◽

Krisztina Bogi ◽

Peter Acs ◽

Patricia S. Lorenzo ◽

Lindsey Baskin ◽

...

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Glutamine Synthetase ◽

Tyrosine Phosphorylation ◽

Glial Cells ◽

Regulatory Domain ◽

Kinase C

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Scanning Mutagenesis Studies Reveal Multiple Distinct Regions within the Human Protein Kinase C Alpha Regulatory Domain Important for Phorbol Ester-dependent Activation of the Enzyme

Journal of Molecular Biology ◽

10.1016/j.jmb.2005.12.056 ◽

2006 ◽

Vol 357 (3) ◽

pp. 820-832 ◽

Cited By ~ 3

Author(s):

Baoqing Guo ◽

Kerry Reed ◽

Amadeo M. Parissenti

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Phorbol Ester ◽

Human Protein ◽

Regulatory Domain ◽

Kinase C ◽

Human Protein Kinase ◽

Protein Kinase C Alpha

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Type 3 protein kinase C localization to the nuclear envelope of phorbol ester-treated NIH 3T3 cells.

The Journal of Cell Biology ◽

10.1083/jcb.109.2.685 ◽

1989 ◽

Vol 109 (2) ◽

pp. 685-695 ◽

Cited By ~ 155

Author(s):

K L Leach ◽

E A Powers ◽

V A Ruff ◽

S Jaken ◽

S Kaufmann

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Cell Surface ◽

Nuclear Envelope ◽

Immunofluorescent Staining ◽

Regulatory Domain ◽

3T3 Cells ◽

Kinase C ◽

Type 3 ◽

Nih 3T3

We have examined the immunocytochemical localization of protein kinase C (PKC) in NIH 3T3 cells using mAbs that recognize Type 3 PKC. In control cells, the immunofluorescent staining was similar with mAbs directed to either the catalytic or the regulatory domain of PKC. Type 3 PKC localized in a diffuse cytoplasmic pattern, while the nuclei were apparently unstained. Cytoskeletal components also were Treatment of the cells with phorbol 12-myristate 13-acetate (PMA) resulted in a redistribution of PKC with a specific increase in nuclear PKC. Compared to control cells, the staining with the anticatalytic domain mAbs changed markedly, covering the entire cell surface. In contrast, the staining by the antiregulatory domain mAb did not cover the cell surface and the nuclei remained unstained; these results suggest that PKC activation leads to a conformational change of the regulatory domain such that the epitope recognized by the antiregulatory domain mAb is not readily accessible. We have demonstrated by three criteria that PMA treatment specifically increased PKC in the nucleus: (a) immunofluorescent staining in isolated nuclei increased; (b) Western blots showed that our mAbs detected only one protein, the 82-kD PKC, whose level increased in nuclear lysates from PMA-treated cells; and (c) PKC activity increased in nuclear lysates. In fractionation studies we demonstrated that PKC specifically localized to the nuclear envelope fraction. These results demonstrate that PMA activation leads to a rapid redistribution of Type 3 PKC to the nuclear envelope, and suggests that this isozyme may play a role in mediating PKC-induced changes in gene expression.

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