scholarly journals Co-ordinated changes in the cyclic AMP signalling system and the phosphorylation of two nuclear proteins of Mr 130,000 and 110,000 during proliferative stimulation of the rat parotid gland by isoprenaline. Possible identity of the two proteins with pp135 and nucleolin

1989 ◽  
Vol 263 (3) ◽  
pp. 785-793 ◽  
Author(s):  
J Hoffmann ◽  
G Schwoch
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Parotid Gland ◽  
Dna Synthesis ◽  
Beta Agonist ◽  
Nuclear Proteins ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
32P Incorporation ◽  
Stimulation Of

Parotid glands were stimulated to growth by repeated injection of the beta-agonist isoprenaline into rats. Incubation of intact parotid-gland lobules with [32P]Pi and subsequent analysis of nuclear proteins revealed in the stimulated glands an increased 32P incorporation into two acid-soluble non-histone proteins with apparent Mr values of 110,000 and 130,000 (p110 and p130). After a single injection of isoprenaline, leading to a biphasic increase in DNA synthesis (maximum at 24 h), the same two proteins showed a transiently increased 32P incorporation at 17 h after injection. At this time point at the onset of DNA synthesis the total activity of soluble cyclic AMP-dependent protein kinase decreased. No change in p110/p130 phosphorylation was observed at 0.3 h after stimulation, a time of maximal stimulation of secretion. Administration of the beta-antagonist propranolol 8 h after the injection of isoprenaline suppressed the increase in DNA synthesis, the preceding changes in the concentration of cyclic AMP and in the activity of cyclic AMP-dependent protein kinase, as well as the increased phosphorylation of p110 and p130. Cross-reactivity of p110 and p130 with specific antisera against two nucleolar phosphoproteins of similar molecular mass (nucleolin and pp135), as well as their localization in a nucleolar cell fraction, indicated a possible identity of p110 and p130 with these two proteins. Our results suggest that nucleolin and pp135 are nuclear target proteins of cyclic AMP in the cyclic AMP-influenced regulation of the transition of cells from the G1 to the S phase.

Stimulation of chick adrenal steroidogenesis by avian parathyroid hormone

1988 ◽  
Vol 116 (1) ◽  
pp. 91-95 ◽  
Author(s):  
J. Rosenberg ◽  
M. Pines ◽  
S. Hurwitz
Keyword(s):  
Parathyroid Hormone ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Steroid Hormone ◽  
Hormone Secretion ◽  
Peptide Hormone ◽  
Adrenocortical Cells ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Stimulation Of

ABSTRACT Dispersed chick adrenocortical cells were incubated with avian parathyroid hormone (aPTH) or ACTH. Accumulation of cyclic AMP (cAMP), activity of cAMP-dependent protein kinase and the secretion of corticosterone and aldosterone, in response to these hormones, were measured. Accumulation of cAMP and activity of cAMP-dependent protein kinase were stimulated by both aPTH and ACTH as well as by cholera toxin. Cyclic AMP production followed a similar time-course when stimulated by either peptide hormone. Stimulation of steroid hormone secretion was detectable after 20 min of incubation with ACTH, but only after 40 min with aPTH. The maximal steroid hormone secretion by adrenocortical cells was similar when induced by either peptide hormone. The aPTH concentrations needed for half-maximal response of corticosterone and aldosterone secretion were higher than those for ACTH (2·5- and 2-fold respectively), but still within the physiological range. The 11β-hydroxylase inhibitor metyrapone inhibited the secretion of both corticosterone and aldosterone when induced by either aPTH or ACTH. The results suggest that aPTH is almost as potent as ACTH in stimulating the secretion of corticosterone and aldosterone from chick adrenocortical cells and utilizes a cAMP-dependent pathway similar to that of ACTH. J. Endocr. (1988) 116, 91–95

Effects of isoproterenol on cylic-AMP metabolism in rat ventral prostate

1976 ◽  
Vol 54 (3) ◽  
pp. 327-335 ◽  
Author(s):  
B. K. Tsang ◽  
R. L. Singhal
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Kinase Activity ◽  
Activity Ratio ◽  
Ventral Prostate ◽  
Adrenergic Stimulation ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Stimulation Of

β-Adrenergic stimulation of the ventral prostate cyclic-AMP system was investigated by examining the influence of isoproterenol on endogenous cyclic-AMP levels as well as on the activities of adenylate cyclase (EC 4.6.1.1) and cyclic-AMP-dependent and independent protein kinases (EC 2.7.1.37). Administration of isoproterenol (1 mg/kg, ip) resulted in rapid elevation of adenylate cyclase activity (119%) and cyclic-AMP levels (593%). The observed isoproterenol-stimulated changes in cyclic-AMP metabolism of the ventral prostate were time-dependent and maximal stimulation was seen 5 min after treatment with this β-adrenergic agonist. The increases in prostatic adenylate cyclase and cyclic-AMP also were related to the dose of isoproterenol administered and maximal enhancement of these parameters was seen with 1 mg/kg dose of the agonist. Whereas pretreatment of rats with propranolol (3 mg/kg, ip) partially reversed these alterations, administration of an α-adrenergic antagonist, phentolamine, even at a dose of 5 mg/kg, failed to elicit any appreciable effect. Stimulation of prostatic soluble protein kinase by isoproterenol was associated with a decrease (33%) in the activity of the cyclic-AMP-dependent protein kinase with a concomitant increase (25%) in that of the independent enzyme. Whereas the ability of the enzyme to bind cyclic-[3H] AMP in vitro was decreased (54%) following isoproterenol treatment, the protein kinase activity ratio (−cyclic-AMP/+cyclic-AMP) was significantly elevated from 0.51 ± 0.05 to 0.95 ± 0.08. Although propranolol alone had little or no effect on these parameters, it inhibited partially the isoproterenol-induced alterations in cyclic-AMP-dependent protein kinase and the cyclic-AMP binding capacity. Treatment with propranolol also blocked the increases in the kinase activity ratio and in the activity of cyclic-AMP-independent enzyme seen with isoproterenol. Data suggest that the concentration of ventral prostate cyclic-AMP as well as the activities of adenylate cyclase and cyclic-AMP-dependent and independent form of protein kinases are subject to modulation by β-adrenergic stimulation.

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