Isoflurane Induces a Protein Kinase C α-Dependent Increase in Cell-Surface Protein Level and Activity of Glutamate Transporter Type 3

2005 ◽  
Vol 67 (5) ◽  
pp. 1522-1533 ◽  
Author(s):  
Yueming Huang ◽  
Zhiyi Zuo
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Surface ◽  
Protein Level ◽  
Glutamate Transporter ◽  
Surface Protein ◽  
Cell Surface Protein ◽  
Kinase C ◽  
Type 3

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

1989 ◽  
Vol 109 (2) ◽  
pp. 685-695 ◽  
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.

Isoflurane Enhances the Expression and Activity of Glutamate Transporter Type 3 in C6 Glioma Cells

2003 ◽  
Vol 99 (6) ◽  
pp. 1346-1353 ◽  
Author(s):  
Yueming Huang ◽  
Zhiyi Zuo
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Glutamate Transporter ◽  
Glioma Cells ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
C6 Cells ◽  
Phosphatidylinositol 3 Kinase ◽  
Kinase C ◽  
Type 3

Background Glutamate transporters play an important role in maintaining extracellular glutamate homeostasis. Volatile anesthetics have been shown to affect glutamate transporter activity acutely (within minutes after the exposure). It is not known whether volatile anesthetics affect the expression of glutamate transporters. Methods Rat cultured C6 glioma cells that express excitatory amino acid transporter type 3 (EAAT3) were exposed to isoflurane at various concentrations (0.5-4.0%) or for different periods (1-24 h) at 37 degrees C. EAAT3 mRNA, proteins, and activity were quantified. Results Isoflurane induced a time- and concentration-dependent increase in the mRNA and protein levels of EAAT3 in C6 cells. The maximal increase was induced by 2% isoflurane, and the cells incubated with 2% isoflurane for 3 and 7 h expressed the highest levels of EAAT3 mRNA and proteins, respectively. Similarly, glutamate uptake was higher in C6 cells exposed to 2% isoflurane for 7 h than in control cells. Actinomycin D and cycloheximide, inhibitors for mRNA and protein synthesis, respectively, did not affect the isoflurane-induced increase in EAAT3 mRNA and protein expression. Phorbol 12-myristate 13-acetate, a protein kinase C activator, also enhanced EAAT3 expression. The combination of 2% isoflurane and phorbol 12-myristate 13-acetate caused a higher level of EAAT3 expression than that induced by 2% isoflurane alone. Neither staurosporine, a protein kinase C inhibitor, nor wortmannin, a phosphatidylinositol 3 kinase inhibitor, inhibited the isoflurane-induced increase in EAAT3 expression. Conclusions The results of this study suggest that isoflurane increases the expression and activity of EAAT3 by stabilizing EAAT3 mRNA and proteins via protein kinase C- and phosphatidylinositol 3 kinase-independent pathways.

scholarly journals Critical Role of S465 in Protein Kinase C-Increased Rat Glutamate Transporter Type 3 Activity

2009 ◽  
Vol 119 (9) ◽  
pp. 1419-1428 ◽  
Author(s):  
Hee Jung Baik ◽  
Yueming Huang ◽  
Jacqueline M. Washington ◽  
Zhiyi Zuo
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Critical Role ◽  
Glutamate Transporter ◽  
Kinase C ◽  
Type 3

scholarly journals Phorbol ester treatment increases the exocytic rate of the transferrin receptor recycling pathway independent of serine-24 phosphorylation.

1988 ◽  
Vol 106 (4) ◽  
pp. 1061-1066 ◽  
Author(s):  
T E McGraw ◽  
K W Dunn ◽  
F R Maxfield
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Surface ◽  
Phorbol Ester ◽  
Cho Cells ◽  
Transferrin Receptor ◽  
Phosphorylation Site ◽  
Major Protein ◽  
Kinase C ◽  
Recycling Pathway

In Chinese hamster ovary (CHO) fibroblast cells the protein kinase C activating phorbol ester, phorbol myristate acetate (PMA), stimulates an increase in cell surface transferrin receptor (TR) expression by increasing the exocytic rate of the recycling pathway. The human TR expressed in CHO cells is similarly affected by PMA treatment. A mutant human TR in which the major protein kinase C phosphorylation site, serine 24, has been replaced with the non-phosphorylatable amino acid glycine has been constructed to investigate the role of receptor phosphorylation in the PMA induced up-regulation. The Gly-24-substituted receptor binds, internalizes, and recycles Tf. Furthermore, the altered receptor mediates cellular Fe accumulation from diferric-Tf, thereby fulfilling the receptor's major biological role. The Gly-24 TR behaves identically to the wild-type TR when cells are treated with PMA. Therefore, Ser-24 phosphorylation is not required for the PMA-induced redistribution of the human TR expressed in CHO cells. The increased TR expression on the cell surface after PMA treatment results from an increase in the rate of exocytosis of the recycling receptors. No change in the endocytic rate or the size of the recycling receptor pool was observed. These results indicate that the PMA effect on the TR surface expression may result from a more general perturbation of membrane trafficking rather than a specific modulation of the TR.

scholarly journals Nedd4-2 but not Nedd4-1 is critical for protein kinase C-regulated ubiquitination, expression, and transport activity of human organic anion transporter 1

2016 ◽  
Vol 310 (9) ◽  
pp. F821-F831 ◽  
Author(s):  
Da Xu ◽  
Haoxun Wang ◽  
Qiang Zhang ◽  
Guofeng You
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Surface ◽  
Organic Anion ◽  
The Body ◽  
Organic Anion Transporter ◽  
Transport Activity ◽  
Kinase C ◽  
Anion Transporter ◽  
In Cells

Human organic anion transporter 1 (hOAT1) expressed at the membrane of the kidney proximal tubule cells mediates the body disposition of a diverse array of clinically important drugs, including anti-HIV therapeutics, antitumor drugs, antibiotics, antihypertensives, and antiinflammatories. Therefore, understanding the regulation of hOAT1 will provide significant insights into kidney function and dysfunction. We previously established that hOAT1 transport activity is inhibited by activation of protein kinase C (PKC) through accelerating hOAT1 internalization from cell surface into intracellular endosomes and subsequent degradation. We further established that PKC-induced hOAT1 ubiquitination is an important step preceding hOAT1 internalization. In the current study, we identified two closely related E3 ubiquitin ligases, neural precursor cell expressed, developmentally downregulated 4-1 and 4-2 (Nedd4-1 and Nedd4-2), as important regulators for hOAT1: overexpression of Nedd4-1 or Nedd4-2 enhanced hOAT1 ubiquitination, reduced the hOAT1 amount at the cell surface, and suppressed hOAT1 transport activity. In further exploring the relationship among PKC, Nedd4-1, and Nedd4-2, we discovered that PKC-dependent changes in hOAT1 ubiquitination, expression, and transport activity were significantly blocked in cells transfected with the ligase-dead mutant of Nedd4-2 (Nedd4-2/C821A) or with Nedd4-2-specific siRNA to knockdown endogenous Nedd4-2 but not in cells transfected with the ligase-dead mutant of Nedd4-1 (Nedd4-1/C867S) or with Nedd4-1-specific siRNA to knockdown endogenous Nedd4-1. In conclusion, this is the first demonstration that both Nedd4-1 and Nedd4-2 are important regulators for hOAT1 ubiquitination, expression, and function. Yet they play distinct roles, as Nedd4-2 but not Nedd4-1 is a critical mediator for PKC-regulated hOAT1 ubiquitination, expression, and transport activity.

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