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Showing papers on "Signal transduction published in 1982"


Book ChapterDOI
TL;DR: This chapter describes the passive modulation of protein phosphorylation and receptor binding by in vitro or in vivo lipid manipulations.
Abstract: Publisher Summary Phosphorylation and dephosphorylation of membrane proteins are intermediate steps in signal transduction by hormones and neurotransmitters. These processes are regulated by cyclic nucleotides and by ions, and are probably dependent on membrane dynamics. Complex, sequential membranal events can be classified into two categories: active (metabolically driven) and passive. Active processes are characterized by energy consumption, (for example, ATP-linked) which can be blocked by metabolic poisons and low temperatures. These processes are long-term in nature and require a specific compartmental strucutre. Most of these processes are associated with the cytoskeletal network. Passive processes, on the other hand, are directly related to diffusion (lateral, rotational or vertical) and are largely determined by membrane lipid fluidity. These processes do not require metabolic energy and can proceed in isolated membranes. Therefore, alteration of membrane lipid fluidity can, passively and instantaneously, modulate receptors, antigens and enzymes. This chapter describes the passive modulation of protein phosphorylation and receptor binding by in vitro or in vivo lipid manipulations.

93 citations


Journal ArticleDOI
TL;DR: The most intensively studied species of the cellular slime molds is Dictyostelium discoideum, and it is a favorable subject because the amebae are activated by chemoattractants in their single-cell phase.

64 citations


Journal ArticleDOI
TL;DR: The findings suggest that parotid gland cells from older rats display an altered alpha-adrenergic signal transduction mechanism at a site between the receptor and phospholipid turnover/Ca2+ mobilization.

57 citations


Journal Article
TL;DR: It is shown that in vivo treatment of L1210 cells with theophylline results in changes in intracellular cyclic AMP-dependent protein kinase activity levels as well as in an apparent redistribution of both the nuclear and cytoplasmic isozymes.
Abstract: Synergistic increases in the survival of mice bearing an L1210 leukemia tumor have been demonstrated previously after treatment with 1,3-bis(2-chloroethyl)-1-nitrosourea together with theophylline over those treated with either agent alone. These results imply that manipulation of cyclic adenosine 3′:5′-monophosphate (cyclic AMP) levels in L1210 cells may result in alteration of sensitivity to chemotherapy and alterations in tumor growth. In the present study, we have shown that in vivo treatment of L1210 cells with theophylline results in changes in intracellular cyclic AMP-dependent protein kinase activity levels as well as in an apparent redistribution of both the nuclear and cytoplasmic isozymes. Biochemical events in the tumor cells immediately after administration of theophylline in vivo or a cyclic AMP analog (8-parachlorophenylthio cyclic adenosine 3′:5′-monophosphate in vitro were independent of the presence of 1,3-bis(2-chloroethyl)-1-nitrosourea. The changes apparently involve signal transduction via the adenylate cyclase system and manifest as: ( a ) increased sensitivity of cyclic AMP-dependent protein kinase to activation by cyclic AMP after treatment of L1210 cells with theophylline; ( b ) decrease in endogenous nuclear protein phosphorylation sites; and ( c ) protein kinase isozyme redistribution between nuclear and extranuclear compartments, i.e. , a relative increase of the type I isozyme activity in the nuclear and of the type II isozyme activity in the 900 × g supernatant fractions after treatment of the mice with theophylline. The relative activity increases are accompanied by a relative decrease of type II activity from the nucleus and type I isozyme activity from the 900 × g extranuclear supernatant fraction. These events appear temporally related to changes in nuclear RNA metabolism as evidenced by altered kinetics of RNA precursor uptake and incorporation into tumor cell RNA after treatment. These results imply that the cyclic AMP-dependent phosphorylative modification of intracellular proteins may play a regulatory role in tumor cell growth and in theophylline-mediated tumor regression.

11 citations


Journal ArticleDOI
02 Sep 1982-Nature
TL;DR: A monoclonal antibody is reported that detects an intracellular protein from macrophages which binds Ca2+ in non-phagocytosing cells, and becomes phosphorylated as a result of phagocyTosis, suggesting it might take part in signal transduction during this process.
Abstract: The macrophage is a highly phagocytic cell which has been widely used in attempts to dissect the mechanisms of endocytosis1. In immune phagocytosis specific interactions occur between ligands on the presenting particle and Fc or C3b specific receptors expressed on the plasma membrane2,3, but macrophages also avidly ingest particles such as polystyrene latex by an immunologically nonspecific mechanism. This process is guided by sequential ligand–receptor interactions4,5. Biochemical studies indicate that actin, myosin and several regulatory components distinct from the troponin system of skeletal muscle, take part in phagocytosis by macrophages and polymorphonuclear leukocytes (PMN)6 and indirect immunofluorescence confirms the presence of these components at sites of phagocytic activity7. However, comparatively little is known about coupling between receptor binding and assembly of the contractile system, although electrical changes8 and the flux of divalent cations9 have been implicated. Here we report a monoclonal antibody that detects an intracellular protein from macrophages which binds Ca2+ in non-phagocytosing cells, and becomes phosphorylated as a result of phagocytosis. It might therefore take part in signal transduction during this process.

10 citations



Book
01 Jun 1982
TL;DR: The mother of the pill, C. Djerassi the NMDA receptor channel - molecular design of a coincidence detector, P.P. Braun et al role of the renin angiotensin system in blood pressure regulation and in human hypertension - new insights from molecular genetics.
Abstract: The mother of the pill, C. Djerassi the NMDA receptor channel - molecular design of a coincidence detector, P.H. Seeburg et al growth hormone-releasing hormone - synthesis and signalling, K.E. Mayo et al signalling mechanisms during the response of pituitary gonadotropes to GnRH, B. Hille et al molecular genetic analysis of cAMP and glucocorticoid signalling in development, J.A. Blendy et al activins and the receptor serine kinase superfamily, D. Gaddy-Kurten et al the MAP kinase cascade, J.S. Campbell et al expression and signal transduction pathways of GnRH receptors, S.S. Stojilkovic and K.J. Catt G protein GAPs - regulation of speed, amplitude and signalling selectivity, E.M. Ross ovarian cell differentiation - a cascade of multiple hormones, cellular signals and regulated genes, J.S. Richards et al oxytocin and oxytocin receptor gene expression in the uterus, H.H. Zingg et al molecular genetic anlaysis of mammalian spermatid differentiation, R.E. Braun et al role of the renin angiotensin system in blood pressure regulation and in human hypertension - new insights from molecular genetics, P. Corvol et al amphibian metamorphosis - a complex programme of gene expression changes controlled by thyroid hormone, D.D. Brown et al the molecular and genetic dissection of the retinoid signalling pathway, P. Chambon an alternative ligand-independent pathway for activation of steroid receptors, B.W. O'Malley et al the endocrine role in mammalian sexual differentiation, J.D. Wilson et al interleukins-1alpha and -1beta in regulation of interleukin-6 expression in Leydig and Sertoli cells, Y. Okuda et al calcitonin gene expression in the rat uterus during pregnancy, Y.Q. Ding et al zone-specific clustering mRNA expression in the rat epididymis, R. Runic et al interleukin-1alpha inhibition of luteinizes human granulosa cell progesterone production through influences on associated white blood cells, C.L. Best and J.A. Hill expression of the "Xenopus laevis" mineralocorticoid receptor during metamorphosis, T. Csikos et al pituitary and hypothalamic regulation of sex differences in serum luteinizing hormone levels in gonadectomized rats - "In Vitro" perifusion studies, A.A. Elskus and N.B. Schwartz derivation of novel embryonic stem cell lines and targeting of cyclic AMP-dependent protein kinase genes, E.P. Brandon et al. (Part contents).