Bidirectional modulation of parathyroid hormone-responsive adenylyl cyclase by protein kinase C

1994 ◽  
Vol 266 (6) ◽  
pp. E897-E904 ◽  
Author(s):  
A. M. Kitten ◽  
T. K. Hymer ◽  
M. S. Katz
Keyword(s):  
Protein Kinase C ◽  
Parathyroid Hormone ◽  
Protein Kinase ◽  
Adenylyl Cyclase ◽  
Catalytic Subunit ◽  
Mrna Levels ◽  
Binding Studies ◽  
Kinase C ◽  
Bidirectional Modulation ◽  
Umr 106

The temporal pattern with which phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C (PKC), modulates parathyroid hormone (PTH)-responsive adenylyl cyclase (AC) was evaluated in a clonal osteoblast-like cell line (UMR-106). Brief (< or = 1 h) exposure of UMR-106 cells to PMA enhanced PTH stimulation of AC, whereas more prolonged PMA treatment decreased the PTH response, with maximum inhibition occurring at < or = 6 h. PMA treatment also resulted in initial activation followed by downregulation of PKC. Exposure of cells to 1,2-dioctanoyl-sn-glycerol, which activated but did not downregulate PKC, resulted in bidirectional modulation of PTH-responsive AC identical to that produced by PMA. Prolonged PMA exposure decreased PTH receptor number, as determined by radioligand binding studies, and reduced PTH receptor mRNA levels, assessed by Northern blot analysis. Forskolin activation of the catalytic subunit of AC was also decreased after prolonged PMA treatment. The results suggest that activation of PKC sequentially stimulates and then inhibits PTH responsiveness. Inhibition of the PTH response occurs by PKC actions exerted on the PTH receptor and the AC catalytic subunit.

Effects of parathyroid hormone and agonists of the adenylyl cyclase and protein kinase C pathways on bone cell proliferation

Bone ◽  
1996 ◽  
Vol 18 (1) ◽  
pp. 59-65 ◽  
Author(s):  
M. Sabatini ◽  
C. Lesur ◽  
M. Pacherie ◽  
P. Pastoureau ◽  
N. Kucharczyk ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Protein Kinase C ◽  
Parathyroid Hormone ◽  
Protein Kinase ◽  
Adenylyl Cyclase ◽  
Bone Cell ◽  
Kinase C ◽  
Bone Cell Proliferation

The role of protein kinase C-δ in PTH stimulation of IGF-binding protein-5 mRNA in UMR-106–01 cells

2002 ◽  
Vol 282 (3) ◽  
pp. E534-E541 ◽  
Author(s):  
Mary S. Erclik ◽  
Jane Mitchell
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Binding Protein ◽  
Specific Inhibitor ◽  
Dominant Negative Mutant ◽  
Nuclear Fraction ◽  
Mrna Levels ◽  
Kinase C ◽  
Umr 106

We have investigated the role of protein kinase C (PKC) signal transduction pathways in parathyroid hormone (PTH) regulation of insulin-like growth factor-binding protein-5 (IGFBP-5) gene expression in the rat osteoblast-like cell line UMR-106–01. Involvement of the PKC pathway was determined by the findings that bisindolylmaleimide I inhibited 40% of the PTH effect, and 1 μM bovine PTH-(3–34) stimulated a 10-fold induction of IGFBP-5 mRNA. PTH-(1–34) and PTH-(3–34) (100 nM) both stimulated PKC-δ translocation from the membrane to the nuclear fraction. Rottlerin, a PKC-δ-specific inhibitor, and a dominant negative mutant of PKC-δ were both able to significantly inhibit PTH-(1–34) and PTH-(3–34) induction of IGFBP-5 mRNA, suggesting a stimulatory role for PKC-δ in the effects of PTH. Phorbol 12-myristate 13-acetate (PMA) stimulated PKC-α translocation from the cytosol to the membrane and inhibited ∼50% of the PTH-(1–34), forskolin, and 8-bromoadenosine 3′,5′-cyclic monophosphate-stimulated IGFBP-5 mRNA levels, suggesting that PKC-α negatively regulates protein kinase A (PKA)-mediated induction of IGFBP-5 mRNA. These results suggest that the induction of IGFBP-5 by PTH is both PKA and PKC dependent and PKC-δ is the primary mediator of the effects of PTH via the PKC pathway.

Protein kinase C differentially modulates PTH- and PGE2-sensitive adenylate cyclase in osteoblast-like cells

1992 ◽  
Vol 262 (1) ◽  
pp. E87-E95
Author(s):  
A. M. Freyaldenhoven ◽  
G. E. Gutierrez ◽  
M. D. Lifschitz ◽  
M. S. Katz
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Enzyme Activation ◽  
Catalytic Subunit ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Osteosarcoma Cell ◽  
Kinase C ◽  
Umr 106

The effects of phorbol 12-myristate 13-acetate (PMA), a known activator of protein kinase C, on receptor-mediated stimulation of adenylate cyclase were evaluated in a rat osteosarcoma cell line (UMR-106) with the osteoblast phenotype. Pretreatment of UMR-106 cells with PMA increased parathyroid hormone (PTH)-stimulated adenylate cyclase activity and inhibited prostaglandin E2 (PGE2)-responsive enzyme activity. In addition, PMA enhanced enzyme activation by forskolin, which is thought to exert a direct stimulatory action on the catalytic subunit of adenylate cyclase. The regulatory effects of PMA were concentration dependent and of rapid onset (less than or equal to 1 min). Treatment with PMA also resulted in translocation of protein kinase C activity from the cytosol to the particulate cell fraction. Pertussis toxin, which attenuates inhibition of adenylate cyclase mediated by the inhibitory guanine nucleotide-binding regulatory protein (Gi), augmented PTH-sensitive adenylate cyclase activity and reduced the incremental increase in PTH response produced by PMA. The results suggest that activation of protein kinase C increases PTH-stimulated adenylate cyclase activity by actions on Gi and/or the catalytic subunit and decreases PGE2 responsiveness by a mechanism involving the PGE2 receptor.

Parathyroid hormone stimulates translocation of protein kinase C isozymes in UMR-106 osteoblastic osteosarcoma cells

Bone ◽  
2001 ◽  
Vol 29 (3) ◽  
pp. 223-230 ◽  
Author(s):  
D.A Dossing ◽  
J.M Radeff ◽  
J Sanders ◽  
S.-K Lee ◽  
M.-R Hsieh ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Parathyroid Hormone ◽  
Protein Kinase ◽  
Osteosarcoma Cells ◽  
Kinase C ◽  
Umr 106 ◽  
Osteoblastic Osteosarcoma

Protein kinase C activating phorbolesters enhance the cyclic AMP response to parathyroid hormone, forskolin and choleratoxin in mouse calvarial bones and rat osteosarcoma cells

1991 ◽  
Vol 11 (4) ◽  
pp. 203-211 ◽  
Author(s):  
Maria Ransjö
Keyword(s):  
Protein Kinase C ◽  
Parathyroid Hormone ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Phorbol Esters ◽  
Osteosarcoma Cells ◽  
Kinase C ◽  
Cyclic Amp Accumulation ◽  
Umr 106

The protein kinase C-(PKC) activating phorbol esters 12-O-tetradecanoylphorbol-13-acetate (TPA; 100 nmol/l) and phorbol 12, 13-dibutyrate (PDBU; 100 nmol/l) enhanced basal cyclin AMP accumulation in cultured neonatal mouse calvaria. The cyclic AMP response to parathyroid hormone (PTH; 10 nmol/l) and the adenylate cyclase activators forskolin (1–3 μmol/l) and choleratoxin (0.1 μmg/ml) was potentiated in a more than additive manner by TPA and PDBU. In contrast, phorbol 13-monoacetate (phorb-13; 100 nmol/l), a related compound but inactive on PKC, had no effect on basal or stimulated cyclic AMP accumulation. In the presence of indomethacin (1μmol/l), TPA and PDBU had no effect on cyclic AMP accumulation in calvarial bones per se, but were still able to cause a significant enhancement of the response to PTH, forskolin and choleratoxin. PTH-, forskolin- and choleratoxin-stimulated cyclic AMP accumulation in rat osteosarcoma cells UMR 106-01 was synergistically potentiated by TPA and PDBU, but not by phorb.-13. These data indicate that PKC enhances cyclic AMP formation and that the level of interaction may be at, or distal to, adenylate cyclase.

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