Protein kinase C-dependent regulation of l-arginine transport activity in Caco-2 intestinal 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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Decrease in equilibrative uridine transport during monocytic differentiation of HL-60 leukaemia: involvement of protein kinase C

Biochemical Journal ◽

10.1042/bj3000407 ◽

1994 ◽

Vol 300 (2) ◽

pp. 407-412 ◽

Cited By ~ 22

Author(s):

C W Lee

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Binding Sites ◽

Plasma Membranes ◽

Nucleoside Transport ◽

Protective Effects ◽

Transport Activity ◽

Monocytic Differentiation ◽

Response Curves ◽

Kinase C

The dose-response curves for the inhibition of equilibrative uridine transport by dilazep, dipyridamole and nitrobenzylthioinosine (NBMPR) in undifferentiated HL-60 cells were biphasic. Some 70% of the transport activity was inhibited with IC50 values of 0.7, 1 and 7 nM respectively. No inhibition of the remaining 30% of transport activity was observed until the dilazep, dipyridamole and NBMPR concentrations exceeded 1, 0.1 and 3 microM respectively. Exposure to phorbol 12-myristate 13-acetate (PMA) for 48 h, to induce monocytic differentiation, caused a 20-fold decrease in Vmax. of both NBMPR-sensitive and NBMPR-insensitive equilibrative uridine transport. The decrease in NBMPR-sensitive uridine transport induced by PMA corresponded to a decrease in NBMPR binding sites. A 30% decrease in specific NBMPR binding sites occurred within 6 h of PMA exposure, and could be prevented by uridine and thymidine at concentrations as low as 100 microM, and by staurosporine at 40 nM. However, the protective effects of these compounds diminished with prolonged PMA exposure. No protection was observed with uracil. Exogenous protein kinase C (PKC) in the presence of ATP and PMA decreased the number of specific NBMPR-binding sites in purified HL-60 cell plasma membranes. These results suggest that a PKC-induced conformational change in substrate-binding/transporting site may be responsible for the decrease in NBMPR-sensitive nucleoside transport during PMA-induced monocytic differentiation of HL-60 cells.

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Inhibitors such as staurosporine, H-7 or polymyxin B cannot be used in skeletal muscle to prove the role of protein kinase C on insulin action

Bioscience Reports ◽

10.1007/bf01121505 ◽

1992 ◽

Vol 12 (5) ◽

pp. 413-424 ◽

Cited By ~ 4

Author(s):

Anna Gumà ◽

Purificación Muñoz ◽

Marta Camps ◽

Xavier Testar ◽

Manuel Palacín ◽

...

Keyword(s):

Skeletal Muscle ◽

Protein Kinase C ◽

Protein Kinase ◽

Insulin Action ◽

Lactate Production ◽

Polymyxin B ◽

Transport Activity ◽

System A ◽

Kinase C

The precise role of protein kinase C in insulin action in skeletal muscle is not well defined. Based on the fact that inhibitors of protein kinase C block some insulin effects, it has been concluded that some of the biological actions of insulin are mediated via protein kinase C. In this study, we present evidence that inhibitors of protein kinase C such as staurosporine, H-7 or polymyxin B cannot be used to ascertain the role of protein kinase C in skeletal muscle. This is based on the following experimental evidences: a) staurosporine, H-7 and polymyxin B markedly block in muscle the effect of insulin on System A transport activity; however, this effect of insulin is not mimicked in muscle by TPA-induced stimulation of protein kinase C, b) H-7 and polymyxin B block insulin action on System A transport activity in an additive manner to the inhibitory effect of phorbol esters, c) staurosporine, H-7 and polymyxin B block the effect of insulin on lactate production, a process that is activated by insulin and TPA in an additive fashion, and d) staurosporine completely blocks the tyrosine kinase activity of insulin receptors partially purified from rat skeletal muscle.

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Melatonin regulates L-arginine transport and NADPH oxidase in young rats with bile duct ligation: role of protein kinase C

Pediatric Research ◽

10.1038/pr.2012.203 ◽

2013 ◽

Vol 73 (1-4) ◽

pp. 395-401 ◽

Cited By ~ 14

Author(s):

You-Lin Tain ◽

Chih-Cheng Chen ◽

Chien-Te Lee ◽

Ying-Hsien Kao ◽

Jiunn-Ming Sheen ◽

...

Keyword(s):

Protein Kinase C ◽

Bile Duct ◽

Protein Kinase ◽

Nadph Oxidase ◽

Bile Duct Ligation ◽

Arginine Transport ◽

Young Rats ◽

Kinase C ◽

Duct Ligation

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Thrombin-induced translocation of GLUT3 glucose transporters in human platelets

Biochemical Journal ◽

10.1042/bj3280511 ◽

1997 ◽

Vol 328 (2) ◽

pp. 511-516 ◽

Cited By ~ 27

Author(s):

R. Lynn SORBARA ◽

Theresa M. DAVIES-HILL ◽

Ellen M. KOEHLER-STEC ◽

J. Susan VANNUCCI ◽

K. McDonald HORNE ◽

...

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Glucose Transport ◽

Glucose Transporter ◽

Glucose Transporters ◽

Human Platelets ◽

Half Time ◽

Transport Activity ◽

Kinase C ◽

Adipose Cells

Platelets derive most of their energy from anaerobic glycolysis; during activation this requirement rises approx. 3-fold. To accommodate the high glucose flux, platelets express extremely high concentrations (155±18 pmol/mg of membrane protein) of the most active glucose transporter isoform, GLUT3. Thrombin, a potent platelet activator, was found to stimulate 2-deoxyglucose transport activity 3-5-fold within 10 min at 25 °C, with a half-time of 1-2 min. To determine the mechanism underlying the increase in glucose transport activity, an impermeant photolabel, [2-3H]2N-4-(1-azi-2,2,2-trifluoethyl)benzoyl-1,3,-bis-(d-mannose-4-ylozy)-2-propylamine, was used to covalently bind glucose transporters accessible to the extracellular milieu. In response to thrombin, the level of transporter labelling increased 2.7-fold with a half-time of 1-2 min. This suggests a translocation of GLUT3 transporters from an intracellular site to the plasma membrane in a manner analogous to that seen for the translocation of GLUT4 in insulin-stimulated rat adipose cells. To investigate whether a similar signalling pathway was involved in both systems, platelets and adipose cells were exposed to staurosporin and wortmannin, two inhibitors of GLUT4 translocation in adipose cells. Thrombin stimulation of glucose transport activity in platelets was more sensitive to staurosporin inhibition than was insulin-stimulated transport activity in adipose cells, but it was totally insensitive to wortmannin. This indicates that the GLUT3 translocation in platelets is mediated by a protein kinase C not by a phosphatidylinositol 3-kinase mechanism. In support of this contention, the phorbol ester PMA, which specifically activates protein kinase C, fully stimulated glucose transport activity in platelets and was equally sensitive to inhibition by staurosporin. This study provides a cellular mechanism by which platelets enhance their capacity to import glucose to fulfil the increased energy demands associated with activation.

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Differential Effects of Calmodulin and Protein Kinase C Antagonists on Bone Resorption and Acid Transport Activity

Calcified Tissue International ◽

10.1007/s00223-002-0012-2 ◽

2003 ◽

Vol 73 (3) ◽

pp. 290-296 ◽

Cited By ~ 6

Author(s):

J. P. Williams ◽

A. M. Thames ◽

M. A. McKenna ◽

J. M. McDonald

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Bone Resorption ◽

Acid Transport ◽

Transport Activity ◽

Differential Effects ◽

Kinase C

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Protein kinase C-dependent phosphorylation of Na(+)-K(+)-ATPase alpha-subunit in rat kidney cortical tubules

AJP Cell Physiology ◽

10.1152/ajpcell.1996.271.1.c136 ◽

1996 ◽

Vol 271 (1) ◽

pp. C136-C143 ◽

Cited By ~ 54

Author(s):

M. L. Carranza ◽

E. Feraille ◽

H. Favre

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Atpase Activity ◽

Rat Kidney ◽

Cation Transport ◽

Dose Dependence ◽

Alpha Subunit ◽

Transport Activity ◽

Kinase C ◽

Gf 109203X

We have previously shown that, in oxygenated rat kidney proximal convoluted tubules (PCT), activation of protein kinase C (PKC) by phorbol 12,13-dibutyrate (PDBu) directly stimulates Na(+)-K(+)-adenosinetriphosphatase (ATPase) activity. PKC modulation of Na(+)-K(+)-ATPase activity by phosphorylation of its alpha-subunit was the postulated mechanism. The present study was therefore designed to investigate the relationship between PKC-mediated phosphorylation of the catalytic alpha-subunit and the cation transport activity of the Na(+)-K(+)-ATPase. In a suspension of rat kidney cortical tubules, activation of PKC by 10(-7) M PDBu increased the level of phosphorylation of the Na(+)-K(+)-ATPase alpha-subunit and stimulated the ouabain-sensitive 86Rb uptake by 47 and 42%, respectively. Time and dose dependence of the PDBu-induced increase in Na(+)-K(+)-ATPase activity and phosphorylation was strongly linearly correlated. The effects of PDBu on phosphorylation and activity of Na(+)-K(+)-ATPase were prevented by GF-109203X, a specific PKC inhibitor, whereas H-89, a specific PKA inhibitor, was ineffective. These results demonstrate that PKC activation induces phosphorylation of the catalytic alpha-subunit of Na(+)-K(+)-ATPase, which may participate in the stimulation of its cation transport activity in the rat PCT.

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