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Nguyen DT, Rovira II, Finkel T. Regulation of the Werner helicase through a direct interaction with a subunit of protein kinase A. FEBS Lett 2002; 521:170-4. [PMID: 12067711 DOI: 10.1016/s0014-5793(02)02868-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Werner syndrome is a hereditary disease characterized by cancer predisposition, genetic instability, and the premature appearance of features associated with normal aging. At the molecular level this syndrome has been related to mutations in the Werner helicase, a member of the RecQ family of DNA helicases which are required to maintain genomic stability in cells. Here we show by a yeast two-hybrid screen that the Werner helicase can directly interact with the regulatory subunit (RIbeta) of cAMP protein kinase A (PKA). We confirm that this interaction occurs in vivo. Interestingly, serum withdrawal causes a redistribution of the Werner helicase within the nucleus of mammalian cells. Raising intracellular cAMP levels or increased expression of the regulatory but not the catalytic subunit of PKA inhibits this nuclear redistribution stimulated by serum deprivation. These results suggest that similar to lower organisms, gene products linked to genomic instability and aging may be directly regulated by growth factor-sensitive, PKA-dependent pathways.
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Affiliation(s)
- Duy T Nguyen
- Cardiovascular Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bldg 10/6N-240, 10 Center Drive, Bethesda, MD 20892-1622, USA
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2
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Mishra N, Khan IU, Tsokos GC, Kammer GM. Association of deficient type II protein kinase A activity with aberrant nuclear translocation of the RII beta subunit in systemic lupus erythematosus T lymphocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:2830-40. [PMID: 10946316 DOI: 10.4049/jimmunol.165.5.2830] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disorder of indeterminate etiology characterized by abnormal T cell signal transduction and altered T cell effector functions. We have previously observed a profound deficiency of total protein kinase A (PKA) phosphotransferase activity in SLE T cells. Here we examined whether reduced total PKA activity in SLE T cells is in part the result of deficient type II PKA (PKA-II) isozyme activity. The mean PKA-II activity in SLE T cells was 61% of normal control T cells. The prevalence of deficient PKA-II activity in 35 SLE subjects was 37%. Deficient isozyme activity was persistent over time and was unrelated to SLE disease activity. Reduced PKA-II activity was associated with spontaneous dissociation of the cytosolic RIIbeta2C2 holoenzyme and translocation of the regulatory (RIIbeta) subunit from the cytosol to the nucleus. Confocal immunofluorescence microscopy revealed that the RIIbeta subunit was present in approximately 60% of SLE T cell nuclei compared with only 2-3% of normal and disease controls. Quantification of nuclear RIIbeta subunit protein content by immunoprecipitation and immunoblotting demonstrated a 54% increase over normal T cell nuclei. Moreover, the RIIbeta subunit was retained in SLE T cell nuclei, failed to relocate to the cytosol, and was associated with a persistent deficiency of PKA-II activity. In conclusion, we describe a novel mechanism of deficient PKA-II isozyme activity due to aberrant nuclear translocation of the RIIbeta subunit and its retention in the nucleus in SLE T cells. Deficient PKA-II activity may contribute to impaired signaling in SLE T cells.
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Affiliation(s)
- N Mishra
- Section on Rheumatology and Clinical Immunology, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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3
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Abstract
The emergence of cisplatin resistance poses a major problem to the successful treatment of a variety of human malignancies. Therefore, understanding the molecular mechanisms that underlie cisplatin resistance could significantly improve the clinical efficacy of this cytotoxic agent. Various studies have described that cellular sensitivity to cisplatin can be influenced by several signal transduction pathways. In this review, we examine the role of the cyclic AMP-dependent protein kinase (PKA) in the modulation of drug resistance in cancer. By a somatic mutant genetic approach, the role of PKA in the development of resistance to chemotherapeutic agents has been investigated. A series of mutants with decreased PKA activity was examined for their sensitivity to cisplatin. PKA mutants with defective regulatory (RIalpha) subunits, but not altered catalytic (C) subunits, exhibit increased resistance to cisplatin, as well as other DNA-damaging agents. Furthermore, since RIalpha subunit mutants show enhanced DNA repair we, therefore, hypothesize that functional inactivation of PKA may result in increased recognition and repair of cisplatin lesions. Alternatively, it seems likely that mutation of the RIalpha subunit may affect cellular sensitivity to various anticancer drugs, suggesting that the RIalpha subunit may have other physiological functions in addition to inhibiting the kinase activity of the C subunit. Therefore, exploitation of cyclic AMP levels or functional alteration of the R subunit may potentiate the cytotoxicity of chemotherapeutic agents and circumvent drug resistance in cancer. More importantly, the altered pattern and mechanism of drug resistance may offer the opportunity to investigate novel regulatory functions of the RIalpha subunit of PKA.
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Affiliation(s)
- M E Cvijic
- Department of Pharmacology, The Cancer Institute of New Jersey, Robert Wood Johnson Medical School, UMDNJ, New Brunswick 08901, USA
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4
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Abstract
The signal transduction pathway of cAMP, mediated by the cAMP-dependent protein kinase (PKA), is involved in the regulation of metabolisms, cell growth and differentiation and gene expression. Isolated PKA mutants from Chinese hamster ovary (CHO) cells were used in our laboratory to study the role of cAMP in the development of drug resistance in cancer. We have found that PKA mutants harboring a defective regulatory (RI alpha) subunit, but not the catalytic (C) subunit, are more resistant to the chemotherapeutic drug cisplatin. To clarify the role of PKA in cisplatin resistance, we have performed a step-wise selection with a CHO RI alpha subunit mutant cell line, 10248, for further resistance to cisplatin. A representative clone (10248/CDDP(R)-5) was used for further characterization. These cisplatin-resistant PKA mutant cells remained refractory to cAMP-induced growth inhibition and had decreased PKA activity comparable to the parental 10248 mutant cells. Furthermore, 10248/CDDP(R)-5 also exhibited cross-resistance to the nitrogen mustard melphalan but maintained the same sensitivity as wild-type cells to non-DNA-damaging agents such as methotrexate. The mechanism of resistance may be due to increased DNA repair as assessed by the host cell reactivation assay. We speculate that mutation and functional inactivation of PKA may result in deregulated growth response to cAMP, as well as the acquisition of resistance to cisplatin and other DNA-damaging agents in cancer.
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Affiliation(s)
- M E Cvijic
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick, USA
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5
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Shinbo M, Niiya K, al-Mokdad M, Hayakawa Y, Hiraga K, Fujimaki M, Sakuragawa N. Protein kinase activity-dependent inhibition of urokinase-type plasminogen activator gene transcription by cyclic AMP in human pre-B lymphoma cell line RC-K8. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1268:293-9. [PMID: 7548228 DOI: 10.1016/0167-4889(95)00088-a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We investigated the effects of cAMP on the urokinase-type plasminogen activator (uPA) production in human pre-B lymphoma cell line RC-K8 that is consistently secreting uPA in the conditioned medium. Both Bt2cAMP and PGE1 inhibited the uPA accumulation in a dose-dependent manner. Northern blot analysis and nuclear run-on assay revealed that uPA gene transcription was repressed by Bt2cAMP and the repression was negated by inhibition of de novo protein synthesis by cycloheximide. Pretreatment with H89 (N-[2-(p-bromocinnamyl-amino) ethyl]-5-isoquinoline sulfonamide), a specific cAMP-dependent protein kinase (PKA) inhibitor, strongly inhibited both the PKA activation and the supression of uPA mRNA accumulation induced by cAMP. H85 (N-[2-(N-formyl-p-chlorocinnamyl-amino) ethyl]-5-isoquinoline sulfonamide), which closely resembles H89 in its chemical structure but is not a selective inhibitor of PKA, showed little effect on the regulation of uPA gene regulation by Bt2cAMP. These results suggest that cAMP represses uPA gene transcription in human pre-B lymphoma cells through PKA pathway and in which de novo protein synthesis is required.
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Affiliation(s)
- M Shinbo
- Department of Clinical Laboratory Medicine Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan
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6
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Sensitization inHelix snail: Morphofunctional correlates in command neurons of withdrawal behavior. NEUROPHYSIOLOGY+ 1994. [DOI: 10.1007/bf01054163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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8
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Nokta MA, Pollard RB. Human immunodeficiency virus replication: modulation by cellular levels of cAMP. AIDS Res Hum Retroviruses 1992; 8:1255-61. [PMID: 1381600 DOI: 10.1089/aid.1992.8.1255] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
HIV infection is associated with qualitative and functional immune deficiencies. It has been shown that the in vitro infection of CD4+ cells with HIV was associated with sustained elevation of cAMP and cGMP. In the present report the role of cAMP on HIV replication in MT-4 cells was investigated. The MT-4 cells were infected with HIV (strain 3b), in the presence or absence of agents that increase intracellular levels of cAMP, through different mechanisms. At selected times postinfection, HIV replication was measured by reverse transcriptase activity or HIV P24Ag in culture supernatants. Forskolin (FK, an activator of adenylate cyclase 1-100 microM), Isobutyl-methylxanthine (IBMX, a phosphodiesterase inhibitor, which indirectly increases intracellular levels of cAMP, 30-100 microM) and dibutyryl (db) cAMP (0.1-10 microM) enhanced HIV replication, in a dose-dependent manner. FK, IBMX, and db cAMP enhanced HIV replication by 2- to 10-fold, 4- to 7-fold, and 2- to 6-fold, respectively. Intracellular levels of cAMP were measured by radioimmunoassay and were also enhanced. Since cAMP exerts its catalytic effects through activation of protein kinase (PK) A the effect of H-8 (a specific inhibitor of the cAMP dependent PK A) on HIV replication was simultaneously examined. The H8 at doses of 0.1 to 10 microns inhibited HIV replication by 25 to 99.9%. Moreover H9 inhibited HIV replication in peripheral blood mononuclear cells by more than 90%. The replication of HIV appears to be a cAMP-dependent event, and PK A could possibly be a target for the development of anti-HIV therapies.
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Affiliation(s)
- M A Nokta
- Department of Internal Medicine, University of Texas Medical Branch, Galveston 77550
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9
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Whisler RL, Beiqing L, Grants IS, Newhouse YG. Cyclic AMP modulation of human B cell proliferative responses: role of cAMP-dependent protein kinases in enhancing B cell responses to phorbol diesters and ionomycin. Cell Immunol 1992; 142:398-415. [PMID: 1320464 DOI: 10.1016/0008-8749(92)90300-e] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The ability of cyclic AMP (cAMP) to modulate human B cell proliferative responses and the possible role of cAMP-dependent kinases (PKA) in cAMP modulation of proliferative responses were investigated. The addition of dibutyl cAMP (Bt2 cAMP) or the cAMP-elevating agent forskolin to B cells stimulated by crosslinking surface immunoglobulins (sIg) resulted in a concentration-dependent inhibition of proliferative responses. By contrast, Bt2 cAMP or forskolin enhanced the proliferative responses of B cells after direct stimulation by phorbol myristate acetate (PMA) and the calcium ionophore ionomycin. The inhibition and enhancement of B cell proliferative responses by Bt2 cAMP were observed at different incubation intervals and were not due to temporal shifts of optimal responses. Also, Bt2 cAMP caused only small changes in B cell RNA synthesis compared to modulation of proliferative responses. Exposure of B cells to Bt2 cAMP rapidly activated PKA. Blocking Bt2 cAMP activation of PKA with the kinase inhibitor HA1004 prevented Bt2 cAMP enhancement of B cell responses after direct stimulation by PMA and ionomycin. In reciprocal experiments, the kinase inhibitor H7 resulted in some inhibition of PKC activation but did not inhibit Bt2 cAMP activation of PKA or Bt2 cAMP enhancement of proliferative responses. Other experiments demonstrated that B cells treated with Bt2 cAMP had selective increases in the de novo phosphorylations of two endogenous substrates which reflected PKA activation. Furthermore, concentrations of HA1004 or H8 which inhibited Bt2 cAMP enhancement of proliferative responses also inhibited PKA phosphorylations of these substrates whereas H7 did not. Thus, elevations of cAMP can enhance or inhibit human B cell proliferative responses to different stimuli and the activation of PKA is important for cAMP enhancement of certain responses.
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Affiliation(s)
- R L Whisler
- William H. Davis Medical Research Center, Ohio State University, Columbus 43210
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Fleischmann RD, Jeng C, Gottesman MM. Ablation of stimulation of a cAMP-responsive promoter in CHO cell lines defective in their cAMP-dependent protein kinase system. ACTA ACUST UNITED AC 1992; 18:103-11. [PMID: 1349445 DOI: 10.1007/bf01233157] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have studied the requirement for an intact cAMP-dependent protein kinase (PKA) system to regulate cAMP-mediated gene transcription in Chinese hamster ovary (CHO) cells. Wild-type CHO cells and mutant CHO cell lines selected for their resistance to the growth inhibitory effect of 8-Br-cAMP and defective in their PKA system were transiently transfected with reporter plasmids containing 2.5 and 3.0 kb of the 5'-flanking sequence of the rat tyrosine aminotransferase (TAT) gene promoter. This segment of DNA contains no CRE-like sequences, yet wild-type transfectants exhibited a specific increase in TAT promoter activity following growth in medium containing 8-Br-cAMP. In CHO cell lines defective in their PKA, the transfected TAT promoter failed to respond to cAMP treatment. We conclude that an intact PKA system is necessary for the cAMP-mediated increase in TAT promoter activity in CHO cells and that there is no requirement for a CRE to see this effect.
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Affiliation(s)
- R D Fleischmann
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
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11
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Prasad KN. Differentiation of neuroblastoma cells: a useful model for neurobiology and cancer. Biol Rev Camb Philos Soc 1991; 66:431-51. [PMID: 1801947 DOI: 10.1111/j.1469-185x.1991.tb01148.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- K N Prasad
- Department of Radiology, School of Medicine, University of Colorado Health Sciences Center, Denver 80262
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12
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Nokta M, Pollard R. Human immunodeficiency virus infection: association with altered intracellular levels of cAMP and cGMP in MT-4 cells. Virology 1991; 181:211-7. [PMID: 1704657 DOI: 10.1016/0042-6822(91)90486-u] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
T-cells from human immunodeficiency virus (HIV)-infected patients are characterized by a number of qualitative deficiencies including defective T-cell activation. The latter has previously been shown to be normally regulated by cAMP. In this study the patterns of cAMP and cGMP induction in MT-4 cells following HIV infection were investigated. The MT-4 cells were infected with HIV (strain IIIb) and at selected times postinfection (p.i.), culture supernatants were tested for HIV replication by reverse transcriptase activity or HIV P24 Ag. The cells were also examined for their intracellular levels of cAMP and cGMP by radioimmunoassay. HIV infection was associated with an increase in intracellular levels of cAMP and cGMP. The cAMP was increased 40-fold by Day 8 and cGMP 4-fold by Day 4 Pl. The increase in intracellular levels of the cyclic nucleotides (CN) were virus specific, dependent on virus dosage, genetically conserved among the two fresh patient isolates tested, and were abolished by uv inactivation. An increase in cAMP and cGMP was also observed in other cell lines infected with HIV. The sustained elevation in CN level observed could certainly influence cell activation and HIV replication and may potentially have clinical relevance.
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Affiliation(s)
- M Nokta
- Department of Internal Medicine, University of Texas Medical Branch, Galveston 77550
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13
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Bradbury AW, Miller WR, Carter DC. Cyclic adenosine 3',5'-monophosphate binding proteins in human colorectal cancer and mucosa. Br J Cancer 1991; 63:201-4. [PMID: 1847645 PMCID: PMC1971789 DOI: 10.1038/bjc.1991.49] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cyclic AMP Binding Proteins (cAMP-BP) levels have been measured by means of a competitive binding assay in the cytosols of 50 human colorectal cancers. These levels have been related to those in mucosa both adjacent to and distant from the tumour in the same patients. Cyclic AMP-BP were higher in tumour than in either adjacent (P less than 0.000001) or distant mucosa (P less than 0.00001). Binding of cAMP in adjacent mucosa was lower than that in distant mucosa (P less than 0.0001). There was no significant difference in the level of binding between tumours arising from different sites in the colon and binding was not related to age or sex of the patient. However, binding was higher in Dukes' B than Dukes' C cancers (P less than 0.005). There was also a trend for cAMP binding levels to be higher in moderately differentiated than in poorly differentiated cancers (P = 0.07). Thus cAMP-BP appear to be over-expressed in human colorectal cancers and levels are related to the stage and grade.
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Affiliation(s)
- A W Bradbury
- University Department of Clinical Surgery, Royal Infirmary, Edinburgh, UK
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14
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Pearson D, Nigg EA, Nagamine Y, Jans DA, Hemmings BA. Mechanisms of cAMP-mediated gene induction: examination of renal epithelial cell mutants affected in the catalytic subunit of the cAMP-dependent protein kinase. Exp Cell Res 1991; 192:315-8. [PMID: 1898592 DOI: 10.1016/0014-4827(91)90193-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The precise mechanistic role of the cAMP-dependent protein kinase (cAMP-PK) in cAMP-mediated gene induction remains unclear. Renal epithelial cell mutants were compared to the LLC-PK1 parental cell line for induction of the cAMP-responsive urokinase-type plasminogen activator (uPA) gene, as quantitated by the technique of mRNA solution hybridization. The FIB4 and FIB6 mutants, which possess less than 10% parental cAMP-PK catalytic (C) subunit activity, showed markedly diminished uPA mRNA induction in response to agents elevating intracellular cAMP such as the cAMP analogue 8-bromo-cAMP and the adenylate cyclase-stimulating hormones vasopressin and calcitonin. In contrast, the mutant cells responded to a similar or greater extent than the parental cells in terms of uPA mRNA induction following treatment with the Ca2+/phospholipid-dependent protein kinase activator phorbol 12-myristate 13-acetate (PMA). Elevation of intracellular cAMP was found to induce a translocation of the cAMP-PK C subunit from the perinuclear Golgi region to the nucleus in both parental and mutant cell lines, as shown by immunocytochemical techniques. Results argue for the role of the cAMP-PK C subunit activity and possibly nuclear translocation of the C subunit in cAMP-mediated uPA induction, which is mechanistically distinct from the PMA-stimulated response.
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Affiliation(s)
- D Pearson
- Friedrich Miescher-Institut, Basel, Switzerland
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15
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Meinkoth JL, Ji Y, Taylor SS, Feramisco JR. Dynamics of the distribution of cyclic AMP-dependent protein kinase in living cells. Proc Natl Acad Sci U S A 1990; 87:9595-9. [PMID: 2263615 PMCID: PMC55219 DOI: 10.1073/pnas.87.24.9595] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The intracellular distribution of regulatory molecules may provide a mechanism for controlling gene expression. The subcellular location of cAMP-dependent protein kinase was analyzed in living cells by microinjection of regulatory and catalytic subunits labeled with fluorescein. Following microinjection, type I holoenzyme was found in the cytoplasm and remained there for up to 4 hr. Upon dissociation of holoenzyme with 8-bromo-cAMP, free catalytic subunit appeared in the nucleus while regulatory subunit remained in the cytoplasm. Similarly, purified catalytic subunit was transported to the nucleus in the absence of elevated intracellular cAMP following its introduction into the cytoplasm. Translocation to the nucleus was apparent within 10 min and persisted for at least 2 hr. In contrast, purified regulatory subunit, like holoenzyme, was maintained in the cytoplasm. These results suggest that one function of the type I regulatory subunit is to serve as a cytoplasmic anchor, sequestering the catalytic subunit in the cytoplasm until holoenzyme dissociates in response to increased cAMP.
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Affiliation(s)
- J L Meinkoth
- Department of Medicine, University of California, San Diego, La Jolla 92093
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16
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Lee BJ, Kim K, Cho WK. Activation of intracellular pathways with forskolin and phorbol ester increases LHRH mRNA level in the rat hypothalamus superfused in vitro. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1990; 8:185-91. [PMID: 2170797 DOI: 10.1016/0169-328x(90)90015-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Two intracellular signal transduction mechanisms such as cAMP-protein kinase a and phosphatidylinositol (PI) turnover-protein kinase c are known to be dually involved in the regulation of luteinizing hormone-releasing hormone (LHRH) release. However, it is not yet evident that the activation of two intracellular pathways affects the LHRH gene expression. The present study aims, therefore, to determine whether the activation of two intracellular pathways affects changes in LHRH mRNA. To this end, we took advantage of an in vitro superfusion system, where rat hypothalamic tissues were superfused with media containing forskolin (FKN) and/or phorbol-12-myristate-13-acetate (PMA). Superfusates were collected at 10-min intervals and LHRH release was determined by radioimmunoassay. After a 2-h superfusion period, the post-superfusion hypothalami were recovered and poly (A) RNA fractions were isolated. Alterations in LHRH mRNA in response to FKN and/or PMA were determined by an RNA-blot hybridization assay using a 32P-end-labeled LHRH oligonucleotide (29-mer) probe. In vitro perfusion of hypothalamic fragments with PMA and/or FKN stimulated LHRH release as well as LHRH mRNA. The combined infusion of FKN and PMA did not produce an additive effect on the LHRH mRNA levels, but it was effective in synergistically increasing LHRH secretion in vitro. These data clearly demonstrate that the biosynthetic machinery of LHRH is influenced by activation of two intracellular pathways, both cAMP-protein kinase a and phosphatidyl-inositol turnover-protein kinase c, indicating the transsynaptic regulation of hypothalamic LHRH gene expression.
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Affiliation(s)
- B J Lee
- Department of Zoology, College of Natural Sciences, Seoul National University, South Korea
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17
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Cannon JF, Gitan R, Tatchell K. Yeast cAMP-dependent protein kinase regulatory subunit mutations display a variety of phenotypes. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38484-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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18
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Gross RE, Lu XY, Rubin CS. Regulation of the expression of the regulatory subunit of cAMP-dependent protein kinase II beta in Friend erythroleukemic cells. Evidence for posttranscriptional control and a central role for the C subunit. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39050-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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19
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Büchler W, Meinecke M, Chakraborty T, Jahnsen T, Walter U, Lohmann SM. Regulation of gene expression by transfected subunits of cAMP-dependent protein kinase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 188:253-9. [PMID: 2156696 DOI: 10.1111/j.1432-1033.1990.tb15397.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
cAMP regulates the expression of several genes by activation of a promoter consensus sequence which functions as a cAMP-response element. Evidence indicated that this is accomplished via cAMP dissociation of cAMP-dependent protein kinase into its regulatory (R) and catalytic (C) subunits. Our investigations of the role of these two subunits in gene expression provide direct and quantitative evidence that the C subunit is required for cAMP stimulation of the cAMP-response element in the vasoactive-intestinal-peptide gene in rat pheochromocytoma cells. After cotransfection of a metallothionein-regulated C-subunit expression vector (pCEV) and a vasoactive-intestinal-peptide--chloramphenicol acetyltransferase construct containing a cAMP-response element, we could demonstrate expression of transfected C-alpha-subunit mRNA (truncated size 1.7 kb) by Northern blot and a concentration-dependent C subunit stimulation of chloramphenicol acetyltransferase activity. Basal activity was stimulated 12- and 50-fold by pCEV (30 micrograms), in the absence and presence, respectively, of Zn2+. Metallothionein-regulated expression of C was demonstrated by results that showed a 2-4-fold increase in chloramphenicol acetyltransferase activity in the presence versus the absence of 90 microM Zn2+. In contrast, overexpression of the R-II beta regulatory subunit did not stimulate chloramphenicol acetyltransferase activity, and R-II beta transfected together with C (ratio 2:1 and 4:1) inhibited the stimulation by the C subunit 70% and 90% respectively. Our results indicate that transfection of cAMP-dependent protein kinase subunits results in functional expression of both C-alpha and R-II beta subunits. Expression of the C subunit mediated cAMP-regulated gene expression but this expression could be inhibited by cotransfected R-II beta subunit, indicating intracellular reconstitution of the inactive holoenzyme of cAMP-dependent protein kinase.
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Affiliation(s)
- W Büchler
- Department of Internal Medicine, University of Würzburg, Federal Republic of Germany
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20
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Affiliation(s)
- E A Nigg
- Swiss Institute for Experimental Cancer Research (ISREC), Epalinges
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21
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Squinto SP, Jungmann RA. Modulation of nuclear cyclic AMP-dependent protein kinase in dibutyryl cyclic AMP-treated rat H4IIE hepatoma cells. Biochem J 1989; 260:673-82. [PMID: 2548485 PMCID: PMC1138730 DOI: 10.1042/bj2600673] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Biochemical and immunochemical studies were undertaken to quantify the effects of cyclic AMP on cyclic AMP-dependent protein kinase subunit levels in nuclei of H4IIE hepatoma cells. Dibutyryl cyclic AMP (10 microM) caused a significant biphasic (10 and 120 min after stimulation) increase in total nuclear protein kinase activity. The increase observed 10 min after dibutyryl cyclic AMP stimulation was primarily due to an approx. 3-fold increase of catalytic (C) subunit activity, whereas the change observed 120 min after stimulation consisted of an increase in both C subunit and cyclic AMP-independent protein kinase activities. Analysis of nuclear protein extracts by photoaffinity labelling with 8-azido cyclic [32P]AMP identified only the type II regulatory subunit (RII), but not the type I regulatory subunit (RI). Analysis of nuclear RII variants by two-dimensional gel electrophoresis demonstrated that dibutyryl cyclic AMP caused the appearance of two RII variant forms which were not present in the nuclei of unstimulated cells. Using affinity-purified polyclonal antibodies and immunoblotting procedures, we identified an approx. 2-fold increase in the RII and C subunits in nuclear extracts of dibutyryl cyclic AMP-treated hepatoma cells. Finally, the RI, RII and C subunits were quantified by an e.l.i.s.a. which indicated that dibutyryl cyclic AMP increased nuclear RII and C subunits levels biphasically, reaching peak values 10 and 120 min after the initial stimulation. Nuclear RI subunit levels were not affected. These results provide qualitative as well as quantitative evidence for a modulation by cyclic AMP of the nuclear RII and C subunit levels in rat H4IIE hepatoma cells, and indicate a relatively rapid but temporarily limited dibutyryl cyclic AMP-induced translocation of the RII and C subunits to nuclear sites.
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Affiliation(s)
- S P Squinto
- Department of Molecular Biology, Northwestern University Medical School, Chicago, IL 60611
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22
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Wu JC, Wang JH. Sequence-selective DNA binding to the regulatory subunit of cAMP-dependent protein kinase. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)81757-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Hand AR, Jungmann RA. Localization of cellular regulatory proteins using postembedding immunogold labeling. THE AMERICAN JOURNAL OF ANATOMY 1989; 185:183-96. [PMID: 2773812 DOI: 10.1002/aja.1001850211] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cyclic AMP-dependent protein kinase (cAPK) mediates the effects of catecholamines and hormones that cause elevation of intracellular cyclic AMP levels. The holoenzyme is a tetramer consisting of catalytic (C) and cyclic AMP-binding regulatory (R) subunits. The type I and type II cAPK isoenzymes are defined by R subunits (RI and RII) of differing molecular weight, primary structure, and cyclic AMP-binding properties. Postembedding immunogold labeling procedures and specific polyclonal and monoclonal antibodies to RI, RII, and C were used to study the subcellular distribution of cAPK subunits in several tissues. In the rat parotid gland, both RI and RII were present in the cytoplasm, nuclei, and secretory granules of the acinar cells, whereas secretory granules of intercalated and striated duct cells were poorly labeled. These results confirmed that the acinar secretory granules are the source of R subunits previously identified in saliva by specific photoaffinity labeling techniques. Zymogen granules of pancreatic acinar cells and secretory granules of seminal vesicle cells were labeled with antibody to RII. Pancreatic and seminal fluids were shown to contain cyclic AMP-binding proteins. The granules of several endocrine cells (pituitary, pancreatic islet, intestinal) also labeled with RII antibody. Double labeling of ovarian granulosa cells showed that both RI and C were present in the nuclei and cytoplasm. The localization of cAPK subunits revealed by postembedding immunogold labeling is consistent with the postulated regulatory functions of these proteins in gene expression, cell proliferation, exocytosis, and various metabolic events The widespread occurrence of cAPK subunits in secretory granules and their release to the extracellular environment suggests that they play an important role in secretory cell function.
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Affiliation(s)
- A R Hand
- National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892
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24
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Ghai J, Das A. The virD operon of Agrobacterium tumefaciens Ti plasmid encodes a DNA-relaxing enzyme. Proc Natl Acad Sci U S A 1989; 86:3109-13. [PMID: 2541431 PMCID: PMC287074 DOI: 10.1073/pnas.86.9.3109] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The virD locus of Agrobacterium tumefaciens Ti plasmid encodes functions necessary for endonucleolytic cleavage of transferred DNA (T-DNA) prior to its transfer to plant cells. For the overproduction of the VIRD proteins in Escherichia coli a tac-virD operon fusion was constructed. A significant increase in the accumulation of VIRD proteins was observed in a lon protease-deficient E. coli host. The presence of an overlapping open reading frame (ORF) upstream of the VIRD1 coding sequence had a negative effect on VIRD1 production. A preparation containing VIRD proteins catalyzes the conversion of supercoiled (form I) DNA to relaxed (form IV) DNA. This activity is similar to that of a DNA topoisomerase. The relaxation activity lacks DNA sequence specificity, requires magnesium ion, and has no requirement for an energy source. Studies with plasmids that had lost defined DNA segments encompassing various virD coding regions showed that VIRD1 is the DNA-relaxing enzyme. In a density gradient centrifugation experiment, the DNA-relaxing activity sedimented as a 21-kDa polypeptide. Earlier studies of Jayaswal et al. [Jayaswal, R., Veluthambi, K., Gelvin, S. & Slightom, J. (1987) (J. Bacteriol. 169, 5035-5045] have shown that in E. coli VIRD2 alone is not sufficient for endonucleolytic cleavage of T-DNA and requires VIRD1 for its activity.
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Affiliation(s)
- J Ghai
- Department of Biochemistry, University of Minnesota, Saint Paul 55108
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25
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Maurer RA. Both Isoforms of the cAMP-dependent Protein Kinase Catalytic Subunit Can Activate Transcription of the Prolactin Gene. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83511-6] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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26
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Laufer R, Changeux JP. Activity-dependent regulation of gene expression in muscle and neuronal cells. Mol Neurobiol 1989; 3:1-53. [PMID: 2679765 DOI: 10.1007/bf02935587] [Citation(s) in RCA: 99] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In both the central and the peripheral nervous systems, impulse activity regulates the expression of a vast number of genes that code for synaptic proteins, including neuropeptides, enzymes involved in neurotransmitter biosynthesis and degradation, and membrane receptors. In recent years, the mechanisms involved in these regulations became amenable to investigation by the methods of recombinant DNA technology. The first part of this review focuses on the activity-dependent control of nicotinic acetylcholine receptor biosynthesis in vertebrate muscle, a model case for the regulation of synaptic protein biosynthesis at the postsynaptic level. The second part summarizes some examples of neuronal proteins whose biosynthesis is under the control of transsynaptic impulse activity. The first, second, and third intracellular messengers involved in membrane-to-gene signaling are discussed, as are possible posttranscriptional control mechanisms. Finally, models are proposed for a role of neuronal activity in the genesis and stabilization of the synapse.
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Affiliation(s)
- R Laufer
- URA, CNRS 0210 Département des Biotechnologies, Institut PASTEUR, Paris, France
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27
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Millington WR, Chronwall BM. Dopaminergic Regulation of the Intermediate Pituitary. NEUROENDOCRINE PERSPECTIVES 1989. [DOI: 10.1007/978-1-4612-3554-5_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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28
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Cyclic Nucleotides. Mol Endocrinol 1989. [DOI: 10.1016/b978-0-12-111230-1.50011-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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29
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Evans HH, Ricanati M, Horng MF, Mencl J. Relationship between topoisomerase II and radiosensitivity in mouse L5178Y lymphoma strains. Mutat Res 1989; 217:53-63. [PMID: 2536134 DOI: 10.1016/0921-8777(89)90036-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The cytotoxic and mutagenic effects of topoisomerase II inhibitors were measured in closely related strains of mouse lymphoma L5178Y cells differing in their sensitivity to ionizing radiation. Strain LY-S is sensitive to ionizing radiation relative to strain LY-R and is deficient in the rejoining of DNA double-strand breaks induced by this agent, whereas 2 radiation-resistant variants of strain LY-S have regained the ability to rejoin these double-strand breaks. We have found that the sensitivity of these cells to m-AMSA, VP-16, and ellipticine is correlated to their sensitivity to ionizing radiation. However, this correlation did not extend to their sensitivities to novobiocin, camptothecin, hydrogen peroxide, methyl nitrosourea and UV radiation. Thus, there appears to be a unique correlation between sensitivity to ionizing radiation and to topoisomerase II inhibitors which stabilize the cleavable complex between the enzyme and DNA. It is possible either that (1) topoisomerase II is altered in strain LY-S and that this enzyme is involved in the repair of DNA double-strand breaks or (2) strain LY-S is deficient in a reaction which is necessary for the repair of DNA double-strand breaks induced by ionizing radiation as well as the repair of DNA damage induced by these topoisomerase II inhibitors. m-AMSA, VP-16, and ellipticine were found to be highly mutagenic at the tk locus in L5178Y strains which are heterozygous for the tk gene but not in a tk hemizygous strain, indicating that these inhibitors induce multilocus lesions in DNA, as does ionizing radiation. The differences in the sensitivity of strains LY-R and LY-S to the topoisomerase II inhibitors were paralleled by differences in the induction of protein-associated DNA double-strand breaks in the 2 strains. This correlation did not extend to the radiation-resistant variants of strain LY-S, however. The variants showed resistance to the cytotoxic effects of the inhibitors relative to strain LY-S, but exhibited DNA double-strand break induction similar to that observed in strain LY-S.
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Affiliation(s)
- H H Evans
- Department of Radiology, Case Western Reserve University, Cleveland, OH 44106
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30
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Vereb G, Gergely P. The role of autophosphorylation of cAMP-dependent protein kinase II in the inhibition of protein phosphatase-1. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1989; 21:1137-41. [PMID: 2555228 DOI: 10.1016/0020-711x(89)90056-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. The inhibition of the catalytic subunit of protein phosphatase-1 (PP-1c) by the regulatory subunit of cAMP-dependent protein kinase II (RII) was studied. 2. Phosphorylation or thiophosphorylation of RII increased its inhibitory potency up to 4- and 6-fold and rendered it competitive with respect to the substrate of PP-1c, phosphorylase a. The Ki values for thiophospho-RII and phospho-RII were 200 and 500 nM, respectively. 3. Though PP-1c was able to release phosphate from phospho-RII, its activity once incubated with phospho-RII, remained inhibited even 80% of the phosphate was released from phospho-RII. 4. The catalytic subunit of cAMP-dependent protein kinase was effective in suspending the inhibition employed either before or after the addition of phospho-RII to PP-1c. 5. No exclusive bindings of thiophospho-RII and heat-stable protein inhibitors to the PP-1c could be proved by double inhibition studies, however some synergism was observed in their effect.
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Affiliation(s)
- G Vereb
- Department of Medical Chemistry, University Medical School, Debrecen, Hungary
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31
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Day RN, Walder JA, Maurer RA. A Protein Kinase Inhibitor Gene Reduces Both Basal and Multihormone-stimulated Prolactin Gene Transcription. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(17)31276-0] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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32
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Ekanger R, Vintermyr OK, Døskeland SO. The amounts of rat liver cyclic AMP-dependent protein kinase I and II are differentially regulated by diet. Biochem J 1988; 256:447-52. [PMID: 2851990 PMCID: PMC1135430 DOI: 10.1042/bj2560447] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
1. The fluctuations in rat hepatocyte volume and protein content in response to dietary perturbations (starvation, protein restriction, refeeding) were accompanied by corresponding fluctuations in the amount of the regulatory (R) and catalytic (C) subunits of cyclic AMP-dependent protein kinase. Thus the intracellular concentration of this key enzyme was adjusted to be near constant. 2. The adjustment of cellular R was accomplished almost exclusively by regulating cytosolic RI (R subunit of type I kinase). The preferential down-regulation of cytosolic RI in response to starvation/protein restriction indicates that particulate RI and cytosolic as well as particulate RII are more resistant to breakdown during general catabolism in the hepatocyte. 3. The diet-induced fluctuations of kinase subunits were uniformly distributed in all populations of parenchymatous hepatocytes, regardless of their size and density. It is thus possible to isolate hepatocytes with uniformly altered RI/RII ratio from livers of rats with different feeding regimens. 4. The binding of endogenous cyclic AMP to RI and RII was similar in livers with high RI/RII ratio (fed rats) and low RI/RII ratio (fasted rats) as well as in hepatocytes isolated from fasted rats. Under the conditions of the experiment (short-term stimulation by glucagon), therefore, neither the dietary state nor the RI/RII ratio seemed to affect the apparent affinity of the isoreceptors for cyclic AMP. However, RI appeared to show a slightly higher co-operativity of intracellular cyclic AMP binding than did RII in all states.
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Affiliation(s)
- R Ekanger
- Department of Anatomy, University of Bergen, Norway
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33
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Riabowol KT, Fink JS, Gilman MZ, Walsh DA, Goodman RH, Feramisco JR. The catalytic subunit of cAMP-dependent protein kinase induces expression of genes containing cAMP-responsive enhancer elements. Nature 1988; 336:83-6. [PMID: 2847055 DOI: 10.1038/336083a0] [Citation(s) in RCA: 155] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Transcriptional regulation of eukaryotic genes by cyclic AMP requires a cAMP-dependent protein kinase (A kinase). Two hypotheses have been proposed to explain how the holoenzyme of the A kinase induces transcription. The regulatory subunits of the A kinase, which bind cAMP and DNA, and have amino-acid homology with the Escherichia coli catabolite activator protein could directly stimulate gene expression. Alternatively, phosphorylation by the catalytic subunits could induce transcription by activating proteins involved in gene transcription. To distinguish between these models, we microinjected purified preparations of the catalytic and regulatory subunits of A kinase into tissue culture cells and monitored expression of a stably integrated fusion gene containing a cAMP-responsive human promoter fused to a bacterial reporter gene, or of the endogenous c-fos gene. The catalytic subunit stimulated expression of these genes, whereas the regulatory subunit did not. These results indicate that the catalytic subunit of A kinase is sufficient to induce expression of two cAMP-responsive genes, without increasing levels of cAMP.
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34
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Deutsch PJ, Hoeffler JP, Jameson JL, Habener JF. Cyclic AMP and phorbol ester-stimulated transcription mediated by similar DNA elements that bind distinct proteins. Proc Natl Acad Sci U S A 1988; 85:7922-6. [PMID: 2847147 PMCID: PMC282325 DOI: 10.1073/pnas.85.21.7922] [Citation(s) in RCA: 145] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
cAMP and phorbol esters mediate cellular metabolism by the activation of distinct signal transduction pathways consisting of a cascade of sequential protein phosphorylations. An important consequence of the activation of these pathways is the stimulation of gene transcription by way of interactions of specific proteins with DNA control elements. The 8-base-pair (bp) DNA consensus sequence TGACGTCA [cAMP response element (cAMP-RE)] has been shown to confer cAMP responsivity on transcription from various promoters, and the closely related 7-bp consensus sequence TGA-(C or G)TCA [phorbol 12-myristate 13-acetate response element (PMA-RE)] lends transcriptional responsiveness to phorbol esters. In the JEG-3 placental cell line we find that several variants of the cAMP-REs fused to a gonadotropin alpha promoter chloramphenicol acetyltransferase reporter gene mediate responsiveness to cAMP but not to phorbol esters. The PMA-RE is responsive to phorbol esters but also imparts submaximal sensitivity to cAMP in the JEG-3 cells and in the Hep G2 hepatoma cell line. The transcriptional activities of cAMP-RE and PMA-RE are markedly influenced by the composition of the neighboring bases, but different sequences are permissive for the activity of the cAMP-RE versus the PMA-RE. The two signaling agents together display a supraadditive effect on reporter genes containing active PMA-REs but not cAMP-REs. Gel-mobility-shift and UV cross-linking analyses show that distinct proteins bind to the two control elements. One protein of 38 kDa binds to the cAMP-RE and several proteins of 48-84 kDa bind to the PMA-RE.
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Affiliation(s)
- P J Deutsch
- Laboratory of Molecular Endocrinology, Massachusetts General Hospital, Boston
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35
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Lord JM, Bunce CM, Brown G. The role of protein phosphorylation in the control of cell growth and differentiation. Br J Cancer 1988; 58:549-55. [PMID: 3064796 PMCID: PMC2246823 DOI: 10.1038/bjc.1988.256] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- J M Lord
- Department of Immunology, University of Birmingham, Edgbaston, UK
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36
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Kwast-Welfeld J, Jungmann RA. Hormonal regulation of nuclear cyclic AMP-dependent protein kinase subunit levels in rat ovaries. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68226-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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37
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Abstract
A cAMP binding protein was detected in HL-60 cells using photoaffinity labeling with 8-azido [32P]cAMP. The binding protein was found in a 0.35 M NaCl nuclear protein extract from untreated HL-60 cells and from the HL-60 cells induced to mature with retinoic acid. While the quantity of the cAMP binding protein did not change following the induced differentiation, a second form of the subunit, altered in charge, was present at 3 and 5 days after retinoic acid treatment. The findings indicate that the regulatory subunit of the type II cAMP-dependent protein kinase could be involved in nuclear functions associated with human myeloid cell differentiation.
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Affiliation(s)
- R C Briggs
- Department of Pathology, A.B. Hancock, Jr. Memorial Laboratory, Vanderbilt University Cancer Center, Nashville, Tennessee
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38
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Roesler WJ, Vandenbark GR, Hanson RW. Cyclic AMP and the induction of eukaryotic gene transcription. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)76506-5] [Citation(s) in RCA: 675] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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39
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Modulation of expression of the stress-inducible p118 of Saccharomyces cerevisiae by cAMP. II. A study of p118 expression in mutants of the cAMP cascade. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68343-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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40
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Lee CQ, Miller HA, Schlichter D, Dong JN, Wicks WD. Evidence for a cAMP-dependent nuclear factor capable of interacting with a specific region of a eukaryotic gene. Proc Natl Acad Sci U S A 1988; 85:4223-7. [PMID: 2454465 PMCID: PMC280399 DOI: 10.1073/pnas.85.12.4223] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Nuclear extracts prepared from the livers of rats treated with or without 8-bromo-cAMP were tested for their ability to bind to various fragments from the flanking region of the gene encoding phosphoenolpyruvate carboxykinase (GTP) [GTP: oxaloacetate carboxy-lyase (transphosphorylating), EC 4.1.1.32] known to contain the element that confers transcriptional regulation by cAMP. Using the nitrocellulose-filtration method, concentration-dependent, apparently saturable binding was seen that is both specific and cAMP dependent. Analysis of various fragments pinpointed the active binding region to positions within the -67 to -111 region, which coincides with the functional regulatory element as shown by recent transfection studies. Formation of an apparently single complex between a synthetic oligomer containing the region from -67 to -111 of the phosphoenolpyruvate carboxykinase gene and a factor in nuclear extracts from cAMP-treated rat liver was visualized by the gel-retardation method. Complex formation is both concentration and cAMP dependent and can be prevented by excess specific but not nonspecific competitor DNA. The congruity of the results with the two different methods suggests that the factor we have detected has properties consistent with a possible role as mediator of the transcriptional control exerted by cAMP in eukaryotic cells.
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Affiliation(s)
- C Q Lee
- Department of Biochemistry, University of Tennessee, Knoxville 37996-0840
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41
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Uno I, Oshima T, Ishikawa T. Localization of the regulatory subunit of cAMP-dependent protein kinase in Saccharomyces cerevisiae. Exp Cell Res 1988; 176:360-5. [PMID: 3288487 DOI: 10.1016/0014-4827(88)90337-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The subcellular distribution of the regulatory subunit of cAMP-dependent protein kinase in Saccharomyces cerevisiae cells was determined by subcellular fractionation and indirect immunofluorescence microscopy using the bcy1 mutant deficient in the regulatory subunit as control. The regulatory subunit of cAMP-dependent protein kinase showing cAMP-binding activity was identified as a single protein of 50 kDa by photoaffinity labeling and immunoblotting. The regulatory subunit was concentrated in a nuclear fraction in addition to a cytoplasmic fraction. By comparison of the regulatory subunit distribution with the DNA localization, the area detected by the indirect immunofluorescence was identified as the nucleus.
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Affiliation(s)
- I Uno
- Institute of Applied Microbiology, University of Tokyo, Japan
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42
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Roger PP, Rickaert F, Huez G, Authelet M, Hofmann F, Dumont JE. Microinjection of catalytic subunit of cyclic AMP-dependent protein kinase triggers acute morphological changes in thyroid epithelial cells. FEBS Lett 1988; 232:409-13. [PMID: 2837413 DOI: 10.1016/0014-5793(88)80781-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In dog thyroid epithelial cells in primary culture, thyrotropin acting through cyclic AMP induced rapid morphological changes associated with complete disruption of actin containing stress fibers. This modification preceded cell retraction and rounding up. These morphological effects were also induced by glass capillary microinjection of purified catalytic subunit of cAMP-dependent protein kinase. This provides the first direct evidence in intact cells that catalytic subunit, which is released upon activation of cAMP-dependent protein kinases, is responsible for cAMP-dependent morphological transformation.
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Affiliation(s)
- P P Roger
- Institut de Recherche Interdisciplinaire, Brussels, Belgium
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43
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Oyen O, Scott JD, Cadd GG, McKnight GS, Krebs EG, Hansson V, Jahnsen T. A unique mRNA species for a regulatory subunit of cAMP-dependent protein kinase is specifically induced in haploid germ cells. FEBS Lett 1988; 229:391-4. [PMID: 3345850 DOI: 10.1016/0014-5793(88)81163-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cyclic AMP (cAMP) and its action by way of cAMP-dependent protein kinase is important for sperm motility. Previous studies on germ cells have demonstrated a selective decrease in the amount of type I cAMP-dependent protein kinase during spermatid development, and that type II was the major form present in elongating spermatids and in mature sperm. This would indicate activation of a gene in haploid germ cells, encoding a regulatory subunit of type II protein kinase. However, haploid expression of such a gene has so far not been shown. In the present study we demonstrate high-levelled expression of a unique mRNA species for a specific regulatory subunit of type II cAMP-dependent protein kinase at late stages of spermatogenesis, i.e. during spermatid elongation.
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Affiliation(s)
- O Oyen
- Institute of Pathology, Rikshospitalet, Oslo, Norway
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44
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Crespi MD, Mladovan AG, Baldi A. Increment of DNA topoisomerases in chemically and virally transformed cells. Exp Cell Res 1988; 175:206-15. [PMID: 2831071 DOI: 10.1016/0014-4827(88)90267-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The activities of topoisomerases I and II were assayed in subcellular extracts obtained from nontumorigenic BALB/c 3T3 A31 and normal rat kidney (NRK) cell lines and from the same cells transformed by benzo[a]pyrene (BP-A31), Moloney (M-MSV-A31) and Kirsten (K-A31) sarcoma viruses, and simian virus 40 (SV-NRK). The enzymatic activity of topoisomerase I was monitored by the relaxation of negatively supercoiled pBR322 DNA and by the formation of covalent complexes between 32P-labeled DNA and topoisomerase I. Topoisomerase II activity was determined by decatenation of kinetoplast DNA (k-DNA). It was found that nuclear and cytoplasmic type I topoisomerase specific activities were higher in every transformed cell line than in the normal counterparts. These differences cannot be attributed to an inhibitory factor present in A31 cells. When chromatin was treated at increasing ionic strengths, the 0.4 M NaCl extract showed the highest topoisomerase I specific activity. Moreover, in this fraction the transformed cells exhibited the most significant increment in the enzymatic activity as compared with nontransformed cultures. Spontaneously transformed A31 cells showed topoisomerase I activity similar to that of extracts of cells transformed by benzo[a]pyrene. Topoisomerase II specific activity was also increased in SV-NRK cells, as judged by the assay for decatenation of k-DNA to yield minicircle DNA.
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Affiliation(s)
- M D Crespi
- Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina
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45
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Sikorska M, Whitfield JF, Walker PR. The regulatory and catalytic subunits of cAMP-dependent protein kinases are associated with transcriptionally active chromatin during changes in gene expression. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)69167-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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46
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Abstract
Growth retardation is the single most common deficit observed in infants exposed to ethanol in utero, and the molecular mechanisms responsible for this growth inhibition are a focus of ongoing research. Several lines of research have suggested that ethanol-induced changes in the adenylate cyclase-protein kinase cascade may be involved in this process. Using an embryonic chick model, it was demonstrated that ethanol exposure during early development caused increases in cellular prostaglandin E2 and cyclic AMP levels that were inversely correlated with brain weight. Paradoxically, basal adenylate cyclase and protein kinase catalytic activities, assayed in vitro, were not altered by ethanol dosing. Ethanol exposure did suppress the responsiveness of brain adenylate cyclase to exogenous PGE2. Furthermore, ethanol treatment significantly lowered the brain cytoplasmic levels of cyclic AMP binding protein.
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Affiliation(s)
- S Pennington
- Department of Biochemistry, ECU School of Medicine, Greenville, North Carolina 27858
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47
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Cobb CE, Corbin JD. Purification of cAMP-free and cAMP-bound forms of bovine heart cAMP-dependent protein kinase holoenzyme. Methods Enzymol 1988; 159:202-8. [PMID: 2842587 DOI: 10.1016/0076-6879(88)59021-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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48
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Lohmann SM, De Camilli P, Walter U. Type II cAMP-dependent protein kinase regulatory subunit-binding proteins. Methods Enzymol 1988; 159:183-93. [PMID: 2842584 DOI: 10.1016/0076-6879(88)59019-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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49
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Veron M, Mutzel R, Lacombe ML, Simon MN, Wallet V. cAMP-dependent protein kinase from Dictyostelium discoideum. DEVELOPMENTAL GENETICS 1988; 9:247-58. [PMID: 3072132 DOI: 10.1002/dvg.1020090407] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The cAMP-dependent protein kinase (cAK) from Dictyostelium discoideum is an enzyme composed of one catalytic and one regulatory subunit. Upon binding of cAMP, the holoenzyme dissociates to liberate free active catalytic subunits. The cAK is developmentally regulated, ranging from very little activity in vegetative cells to maximal expression in postaggregative cells. Although there is no immunological cross-reaction between the subunits of cAKs from Dictyostelium and from other organisms, they share several biochemical properties. A complete cDNA for the regulatory subunit has been cloned and sequenced. Only one copy of the gene for the regulatory subunit is present per haploid genome. On the basis of the comparison of the structure of the cAK from Dictyostelium with its counterparts in yeast and higher eukaryotes, we propose a model for the evolution of cyclic-nucleotide-binding proteins.
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Affiliation(s)
- M Veron
- Unité de Biochimie Cellulaire, Institut Pasteur, Paris, France
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Saraswat LD, Filutowics M, Taylor S. Expression and mutagenesis of the regulatory subunit of cAMP-dependent protein kinase in Escherichia coli. Methods Enzymol 1988; 159:325-36. [PMID: 3045499 DOI: 10.1016/0076-6879(88)59033-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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