cAMP-dependent protein kinase regulates renal epithelial cell properties

1991 ◽  
Vol 260 (6) ◽  
pp. C1290-C1299 ◽  
Author(s):  
K. Amsler ◽  
S. Ghatani ◽  
B. A. Hemmings
Keyword(s):  
Protein Kinase ◽  
Epithelial Cell ◽  
Cell Line ◽  
Cell Junctions ◽  
Kinetic Properties ◽  
Wild Type ◽  
Dependent Protein Kinase ◽  
Renal Epithelial Cell ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein

Previous studies have implicated adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase (PKA) in regulation of both growth and expression of differentiated function in the pig renal epithelial cell, LLC-PK1. To investigate this possible regulatory mechanism, we compared growth behavior, morphology, and appearance of two differentiated functions, Na-hexose symport (SYMP) and gamma-glutamyl transpeptidase (gamma-GT), in the LLC-PK1 line and two PKA-deficient mutants (FIB4 and FIB6). Compared with the wild-type cell line, the mutant lines continued to proliferate at higher population densities and exhibited altered cell morphology, poorer formation of the brush-border structure, and decreased or lack of expression of SYMP and gamma-GT activities. Wild-type and mutant cells exhibit an identical logarithmic growth rate. Both lines form cell-cell junctions and exhibit identical kinetic properties of expressed SYMP activity. These results strongly support the hypothesis that PKA modulates a defined subset of cellular processes, including aspects of growth control and expression of the differentiated phenotype, in this renal epithelial cell line.

Expression of Wild-type and Mutant Subunits of the cAMP-dependent Protein Kinase

1988 ◽  
Vol 53 (0) ◽  
pp. 111-119 ◽  
Author(s):  
G.S. McKnight ◽  
G.G. Cadd ◽  
C.H. Clegg ◽  
A.D. Otten ◽  
L.A. Correll
Keyword(s):  
Protein Kinase ◽  
Wild Type ◽  
Dependent Protein Kinase ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein

Regulation of lung epithelial cell morphology by cAMP-dependent protein kinase type I isozyme

2001 ◽  
Vol 280 (6) ◽  
pp. L1282-L1289 ◽  
Author(s):  
Stephanie E. Porter ◽  
Lori D. Dwyer-Nield ◽  
Alvin M. Malkinson
Keyword(s):  
Protein Kinase ◽  
Cell Junctions ◽  
Actin Binding ◽  
Regulatory Subunit ◽  
Type I ◽  
Stable Transfection ◽  
Dependent Protein Kinase ◽  
Camp Dependent Protein Kinase ◽  
Lung Epithelial ◽  
Dependent Protein

Cell shape is mediated in part by the actin cytoskeleton and the actin-binding protein vinculin. These proteins in turn are regulated by protein phosphorylation. We assessed the contribution of cAMP-dependent protein kinase A isozyme I (PKA I) to lung epithelial morphology using the E10/E9 sibling cell lines. PKA I concentration is high in flattened, nontumorigenic E10 cells but low in their round E9 transformants. PKA I activity was lowered in E10 cells by stable transfection with a dominant negative RIα mutant of the PKA I regulatory subunit and was raised in E9 cells by stable transfection with a wild-type Cα catalytic subunit construct. Reciprocal changes in morphology ensued. E10 cells became rounder and grew in colonies, their actin microfilaments were disrupted, and vinculin localization at cell-cell junctions was diminished. The converse occurred in E9 cells on elevating their PKA I content. Demonstration that PKA I is responsible for the dichotomy in these cellular behaviors suggests that manipulating PKA I concentrations in lung cancer would provide useful adjuvant therapy.

Beta-adrenoceptor metabolism in wild-type, Gs, and protein kinase A-variant S49 cells

1990 ◽  
Vol 259 (1) ◽  
pp. C41-C46 ◽  
Author(s):  
J. R. Jasper ◽  
H. J. Motulsky ◽  
L. C. Mahan ◽  
P. A. Insel
Keyword(s):  
Protein Kinase ◽  
Adrenergic Receptors ◽  
Protein Kinase Activity ◽  
Wild Type ◽  
Beta Adrenergic Receptors ◽  
Dependent Protein Kinase ◽  
Beta Adrenergic ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein ◽  
Gs Alpha

To determine the role of the stimulatory guanine nucleotide-binding protein, Gs, and adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase in the basal metabolism of beta-adrenergic receptors in S49 lymphoma cells, we measured the return of receptor number and function after irreversible blockade of receptors. After inactivation of receptors with the irreversible ligand N8-(bromoacetyl)-N'-[3-(4-indolyoxy)-2-hydroxypropyl]-(2)-1,8-diam ino-p- methane (BIM), beta-adrenergic receptors (defined as [125I]iodocyanopindolol binding sites) reappeared in a biphasic manner, the faster phase having a half-time (t 1/2) of 3-8 h (approximately 50% of the sites) and the slower phase greater than 40 h. Although the slow phase is not readily explained, recovery of binding sites during the first 10 h matched recovery of receptor function after BIM treatment (as measured by stimulation of cAMP accumulation) and recovery of receptor sites after downregulation induced by the agonist isoproterenol. Thus quantifying receptor recovery during the first 10 h after BIM treatment appears to be a reasonable method for examining basal receptor metabolism in S49 cells. Measured in this way, metabolism of beta-adrenergic receptors is very similar in wild-type S49 and the following variant clones: cyc- (absent Gs alpha), UNC and H21a (defective Gs alpha), and kin- (lacking cAMP-dependent protein kinase activity). Although previous data have demonstrated that agonist-promoted downregulation of beta-adrenergic receptors requires functional receptor-Gs coupling, the current data suggest that neither Gs nor cAMP-dependent protein kinase activity plays an important role in the regulation of basal metabolism of beta-adrenergic receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals cAMP-dependent protein kinase activation inhibits proliferation and enhances apoptotic effect of tumor necrosis factor-α in NCI-H295R adrenocortical cells

2004 ◽  
Vol 33 (2) ◽  
pp. 511-522 ◽  
Author(s):  
J Liu ◽  
X-D Li ◽  
A Ora ◽  
P Heikkilä ◽  
A Vaheri ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cell Line ◽  
Adrenocortical Cell ◽  
Dependent Protein Kinase ◽  
Kinase Activation ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein ◽  
H295r Cells ◽  
Induced Apoptosis ◽  
Factor Α

Adrenocorticotropin is the major regulator of adrenocortical development and function. It acts mainly through the cAMP-dependent protein kinase A (PKA) pathway. Our aim was to study the interaction of tumor necrosis factor-α (TNFα) and the PKA pathway in adrenocortical cell proliferation and apoptosis. The PKA activator Dibutyryl cAMP ((Bu)2cAMP) strongly induced differentiation and inhibited proliferation in the human adrenocortical cell line NCI-H295R (H295R). TNFα induced apoptosis of H295R cells. Interestingly, (Bu)2cAMP treatment clearly enhanced TNFα-induced apoptosis in H295R cells, but not in another human adrenocortical cell line SW-13, the mouse adrenocortical Y-1 cell line or the human HeLa cell line. This synergistic effect was not due to the (Bu)2cAMP-induced glucocorticoid secretion since dexamethasone had no significant effect on the TNFα-induced apoptosis. (Bu)2cAMP treatment rapidly increased the expression of the proto-oncogene c-myc in H295R cells, but not in SW-13, Y-1 or HeLa cells. In transient c-myc transfection assay, c-myc expression associated with decreased expression of the proliferation marker Ki-67 in H295R cells. In conclusion, cAMP-dependent protein kinase activation reduced proliferation and augmented TNFα-induced apoptosis in adrenocortical H295R cells, and these effects were associated with increased c-myc expression.

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