Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Heterotrimeric G-proteins function as signal transducers for a variety of hormone-coupled enzyme systems in eukaryotic cells. In LLC-PK1 renal cells, vasopressin-stimulated adenylylcyclase activity is regulated in part, by the counterbalancing activity of stimulatory G-proteins (Gs) and inhibitory pertussis toxin-sensitive G-proteins (Gi). Two Gi genes encoding the Gi isoforms G alpha i-2 and G alpha i-3 are expressed in LLC-PK1 cells. In polarized cells, these isoforms are topographically segregated to different membranes, which allows for the selective inhibition of adenylylcyclase by G alpha i-2. The genes encoding these isoforms are similarly regulated in these cells during growth and differentiation but differ in response to steroid hormone signals (Holtzman, E.J., Kinane, T.B., West, K., Soper, B.W., Karga, H., Ausiello, D.A., and Ercolani, L. (1993) J. Biol. Chem. 268, 3964-3975). We now demonstrate after stimulating polarized LLC-PK1 cells with forskolin, which raises intracellular cAMP levels 50-fold, G alpha i-2 but not G alpha i-3 protein is increased 3-fold at 12 h and remains elevated above control values by 24 h. In cells stably transfected with G alpha i-2 or G alpha i-3 gene 5'-flanking sequences fused to firefly luciferase cDNA reporter gene, forskolin treatment increased G alpha i-2 transcription 3-fold but inhibited G alpha i-3 transcription by 50% at 12 h. In vivo footprinting of forskolin-treated cells was performed to examine the molecular basis for activation of the G alpha i-2 gene. Protected guanosines were identified in a 135-base pair (bp) area previously associated with enhancer activity of this gene in non-polarized cells. This DNA segment did not contain the classical cAMP response element 5'-TGACGTCA-3'. Utilizing the 135-bp DNA segment as a probe in mobility shift assays, which compared nuclear extracts from cells before and after forskolin treatment, an induced nuclear protein complex was identified. Following systematic reduction and mutation of this DNA segment, a "CCAAT" box motif was identified that bound the induced nuclear protein complex during forskolin-induced G alpha i-2 gene transcriptional activation. Induction of this nuclear protein complex was prevented in forskolin-treated cells by cycloheximide. To demonstrate functional activity of the CCAAT box motif, cells were transiently transfected with plasmids encoding either the minimal 135-bp segment or a multimerized CCAAT box segment fused to a Rous sarcoma minimal promoter/firefly luciferase reporter gene.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:cAMP regulates G-protein alpha i-2 subunit gene transcription in polarized LLC-PK1 cells by induction of a CCAAT box nuclear binding factor. 822 26

Vasopressin is synthesized by magnocellular neurons in supraoptic (SON) and paraventricular (PVN) hypothalamic nuclei and released by their axon terminals in the neurohypophysis (NH). With its actions as an antidiuretic hormone and vasoactive agent, vasopressin plays a pivotal role in the control of body fluids and cardiovascular homeostasis. Because of its well-defined neurobiology and functional importance, the SON/PVN-NH system is ideal to establish methods for gene transfer of genetic material into specific pathways in the mouse central nervous system. In these studies, we compared the efficiency of transferring the gene lacZ, encoding for beta-galactosidase (beta-gal), versus a gene encoding for green fluorescent protein by using replication-deficient adenovirus (Ad) vectors in adult mice. Transfection with viral concentrations up to 2 x 10(7) plaque-forming units per coverslip of NH, PVN, and SON in dissociated, cultured cells caused efficient transfection without cytotoxicity. However, over an extended period of time, higher levels (50% to 75% of the cells) of beta-gal expression were detected in comparison with green fluorescent protein (5% to 50% of the cells). With the use of a stereotaxic approach, the pituitary glands of mice were injected with Ad (4 x 10(6) plaque-forming units). In material from these animals, we were able to visualize the expression of the beta-gal gene in the NH and in magnocellular neurons of both the PVN and SON. The results of these experiments indicate that Ad-Rous sarcoma virus promoter-beta-gal is taken up by nerve terminals at the injection site (NH) and retrogradely transported to the soma of the neurons projecting to the NH. We conclude that the application of these experimental approaches will provide powerful tools for physiological studies and potential approaches to deliver therapeutic genes to treat diseases.
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PMID:Adenovirus-mediated gene delivery to hypothalamic magnocellular neurons in mice. 1052 56