Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

7B2 is a 23-kDa protein encoded by a single gene that is expressed in a variety of neuroendocrine tissues. Although its physiological role has not yet been elucidated, its presence in secretory granules suggests a function in the secretory machinery of certain neuronal and endocrine cells in various species. The present study characterizes the expression of 7B2 in endocrine pancreatic cells. We demonstrate that: (i) 7B2 is highly expressed in human insulinomas; (ii) its ultrastructural localization, associated with secretory granules of A and B cells of the islets, suggests a participation of 7B2 in the secretion of insulin and glucagon; (iii) sequences located in the first intron of the 7B2 gene are required for its transcription in either insulinoma or glucagonoma cell lines; and (iv) in a B cell-like insulinoma cell line, the transcription of 7B2 is regulated by protein kinase A and protein kinase C activators, while in an A-like insulinoma cell line, 7B2 gene transcription seems to be constitutively activated.
 ...
PMID:Expression, intracellular localization, and gene transcription regulation of the secretory protein 7B2 in endocrine pancreatic cell lines and human insulinomas. 751 67

In this report we demonstrate that approximately 1.1 kb of the rat glucagon gene promoter upstream of the transcriptional start site specifically directs the transcription of the reporter gene chloramphenicol acetyl transferase (CAT) (p[-1.1]GLU-CAT) in insulinoma beta-TC1 cells. On the contrary, the 350 bp closest to the transcription start site (p[-0.35]GLU-CAT) are ineffective in beta-TC1 cells. Both constructs are transcriptionally active in InR1-G9 glucagonoma cells. While protein kinase A and protein kinase C activators, acting through independent pathways, strongly increase both the transcription of p[-1.1]GLU-CAT and the accumulation of glucagon transcript in beta-TC1 cells, they are weaker activators in InR1-G9 cells. Our experiments suggest that some positive transcription control elements, necessary for the glucagon gene transcription in insulinoma beta-TC1 cells, are localized in the -350/-1100 region of the glucagon gene. Furthermore, our data indicate that glucagon gene transcription can be strongly activated through the protein kinase A pathway in some specific cellular contexts.
 ...
PMID:The glucagon gene is transcribed in beta-like pancreatic cells. 779 81

We characterized somatostatin receptors expressed in hamster glucagonoma INR1G9 cells and the effects of somatostatin on glucagon secretion, proglucagon gene expression, and the adenosine 3',5'-cyclic monophosphate (cAMP)-dependent signal-transduction cascade. 125I-labeled somatostatin was displaced by somatostatin-14 and somatostatin-28 with a dissociation constant of 2 nmol/l. Stable GTP analogues decreased binding of 125I-somatostatin to its receptors, suggesting an interaction of somatostatin receptors with G proteins. Chemical cross-linking of 125I-somatostatin to its receptor revealed a molecular mass of the ligand-receptor complex of 47 kDa. Somatostatin inhibited forskolin-stimulated activation of adenylate cyclase [2.5 microM forskolin (161%) + 1 microM somatostatin (128%); P < 0.05] and protein kinase A [10 microM forskolin (143%) + 1 microM somatostatin (114%); P < 0.05] but did not influence basal activities of these enzymes. Forskolin-induced stimulation of cAMP generation was reduced by somatostatin [2.5 microM forskolin (306%) + 1 microM somatostatin (145%); P < 0.05]. Somatostatin inhibited forskolin, theophylline, and arginine stimulation of glucagon secretion. Basal as well as forskolin-, theophylline-, and isobutyl methylxanthine-induced proglucagon gene expression was significantly reduced by somatostatin. Our data show that, in INR1G9 cells, somatostatin receptors are at least in part coupled to the adenylate cyclase system. Somatostatin is a potent negative regulator of both basal and forskolin-stimulated proglucagon gene expression. The interaction with forskolin occurs at the level of adenylate cyclase. The effect of somatostatin on basal proglucagon gene transcription is most probably mediated by an unrelated second messenger system. Somatostatin may influence several functions of the pancreatic A cell.
 ...
PMID:Functional characterization of somatostatin receptors expressed on hamster glucagonoma cells. 784 Jan 80