scholarly journals Activation of cAMP-dependent protein kinase alters the chromatin structure of the urokinase-type plasminogen activator gene promoter

1994 ◽  
Vol 22 (4) ◽  
pp. 569-575 ◽  
Author(s):  
Janet S. Lee ◽  
Luigi Catanzariti ◽  
Brian A. Hemmings ◽  
Birgitta Kiefer ◽  
Yoshikuni Nagamine
Keyword(s):  
Protein Kinase ◽  
Plasminogen Activator ◽  
Chromatin Structure ◽  
Gene Promoter ◽  
Dependent Protein Kinase ◽  
Camp Dependent Protein Kinase ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator ◽  
Dependent Protein

Receptor-mediated endocytosis of urokinase-type plasminogen activator is regulated by cAMP-dependent protein kinase

1997 ◽  
Vol 110 (12) ◽  
pp. 1395-1402 ◽  
Author(s):  
L. Goretzki ◽  
B.M. Mueller
Keyword(s):  
Protein Kinase ◽  
Plasminogen Activator ◽  
Kinase Inhibitors ◽  
Melanoma Cells ◽  
Protein Kinase Inhibitors ◽  
Dependent Protein Kinase ◽  
Camp Dependent Protein Kinase ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator ◽  
Dependent Protein

Internalization of the urokinase-type plasminogen activator (uPA) requires two receptors, the uPA receptor (uPAR) and the low density lipoprotein receptor-related protein (LRP)/alpha2-macroglobulin (alpha2M) receptor. Here, we address whether protein kinases are involved in the internalization of uPA by human melanoma cells. Initially, we found that the internalization of uPA was significantly inhibited by the serine/threonine protein kinase inhibitors staurosporine, K-252a and H-89, but not by the tyrosine kinase inhibitors, genistein and lavendustin A. Internalization of uPA was also inhibited by a pseudosubstrate peptide for cAMP-dependent protein kinase (PKA), but not by a pseudosubstrate peptide for protein kinase C. We confirmed a requirement for PKA-activity and implicated a specific isoform by using an antisense oligonucleotide against the regulatory subunit RI alpha of PKA which suppresses PKA-I activity. Exposure of cells to this oligonucleotide led to a specific, dose-dependent decrease in RI alpha protein and to a significant inhibition in the rate of uPA internalization. We further demonstrate that treatment of melanoma cells with either H-89 or PKA RI alpha antisense oligonucleotides also resulted in a decreased internalization of two other ligands of LRP, activated alpha2M and lactoferrin, indicating that PKA activity is associated with LRP. Finally, we demonstrate that PKA activity is also required for the internalization of transferrin, but not for the internalization of the epidermal growth factor or adenovirus 2, suggesting that in melanoma cells, PKA activity is not generally required for clathrin-mediated endocytosis, but is rather associated with specific internalization receptors.

Involvement of cyclic adenosine monophosphate-dependent protein kinase isozymes in tissue plasminogen activator secretion by rat Sertoli cells stimulated with follicle-stimulating hormone in vitro

1993 ◽  
Vol 128 (6) ◽  
pp. 555-562 ◽  
Author(s):  
V Laurent-Cadoret ◽  
F Guillou ◽  
Y Combarnous
Keyword(s):  
Protein Kinase ◽  
Plasminogen Activator ◽  
Sertoli Cells ◽  
Tissue Type ◽  
Type I ◽  
Dependent Protein Kinase ◽  
Tissue Type Plasminogen Activator ◽  
Camp Dependent Protein Kinase ◽  
Type Plasminogen Activator ◽  
Dependent Protein

This study was undertaken to investigate, in freshly isolated rat Sertoli cells, the physiological function of the type I and type II cyclic adenosine monophosphate (cAMP)-dependent protein kinase isozymes in tissue-type plasminogen activator secretion and the regulation of this cAMP process by follicle-stimulating hormone (FSH). Follicle-stimulating hormone-induced tissue-type plasminogen activator secretion depends upon intracellular cAMP levels. The changes in cAMP amounts required to activate maximally the tissue-type plasminogen activator secretion are extremely small, a cAMP threshold having to be reached for triggering the tissue-type plasminogen activator output. Intact Sertoli cells were incubated with combinations of cAMP analogs specific for each cAMP-dependent protein kinase type and complementary in their cAMP binding site on the cAMP-dependent protein kinase regulatory subunits: 8-aminohexylamino-cAMP = type 1, site 1; 8-thiomethyl-cAMP = type II, site 1 and N6-benzoyl-cAMP = types I/II, site 2. This allowed us to activate selectively each cAMP-dependent protein kinase type in a synergistic manner and then to evaluate their respective influence in the specific tissue-type plasminogen activator response. We establish that both of the cAMP-dependent protein kinase types are present and functional; the activity of the type I isozyme is preponderant (60%) in the cAMP-dependent tissue-type plasminogen activator secretion. Likewise, when these cAMP analogs were coupled with endogenously generated cAMP by FSH or forskolin, both of the cAMP-dependent protein kinase types were involved in the tissue-type plasminogen activator production. However, only tissue-type plasminogen activator secretion induced by FSH is mediated predominantly by the type I cAMP-dependent protein kinase, although the type II isozyme sustains an appreciable physiological role in the transmission pathway. We suggest some differences in the pattern of action between FSH and forskolin in Sertoli cells.

scholarly journals Dependence of urokinase-type-plasminogen-activator induction on cyclic AMP-dependent protein kinase activation in LLC-PK1 cells

1987 ◽  
Vol 243 (2) ◽  
pp. 413-418 ◽  
Author(s):  
D A Jans ◽  
T J Resink ◽  
B A Hemmings
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Plasminogen Activator ◽  
Cell Lines ◽  
Catalytic Subunit ◽  
Dependent Protein Kinase ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator ◽  
Dependent Protein

The activation of cyclic AMP-dependent protein kinase (cAMP-PK) in vivo was studied in LLC-PK1 pig kidney cells and the mutant cell lines M18 and FIB5, which have total levels of cAMP-PK catalytic-subunit and regulatory-subunit activities comparable with those of parental cells. The extent of cAMP-PK activation (release of active catalytic subunit from the holoenzyme) was directly correlated with the cellular cyclic AMP concentration in LLC-PK1 cells. In LLC-PK1 cells, as well as in the mutants M18 and FIB5, the extent of the induction of urokinase-type plasminogen activator (uPA) by the cyclic AMP-mediated effectors calcitonin, vasopressin and forskolin was directly correlated with the levels of activated catalytic subunit. The ‘receptorless’ mutant M18, which is impaired in calcitonin- and vasopressin-receptor function, did not show any activation of cAMP-PK or uPA production in response to either hormone, whereas cAMP-PK and uPA responses to forskolin were about 35% higher than in parental cells. Analysis of the FIB5-cell line revealed a lesion affecting the regulation of adenylate cyclase activity, whereby basal and stimulated (both receptor- and non-receptor-mediated) adenylate cyclase levels were less than 36% of those in parental cells. The activation of cAMP-PK in response to cyclic AMP effectors was similarly reduced, and uPA induction was concomitantly lower than that in parental cells. The results demonstrate the dependence of uPA induction by cyclic AMP effectors on dissociation of the cAMP-PK holoenzyme, implying the importance of activated free cAMP-PK catalytic subunit in this process. Thus it is concluded that the mutations in the cellular cyclic AMP-generating apparatus of the M18 and FIB5 cell lines impair uPA induction by preventing cAMP-PK activation.

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