Isoproterenol/tannin-dependent R15 expression in transgenic mice is mediated by an upstream parotid control region.
Transgenic mice were used to locate the cis-acting DNA elements that are essential for tissue-specific and inducible expression of the rat proline-rich protein gene, R15. Chimeric genes with up to 10 kb of R15 5'-flanking region fused to chloramphenicol acetyltransferase (CAT) or polyomaviral large T-antigen (PyLT) reporter genes were tested. Our results demonstrate that (1) the isoproterenol/tannin-inducible, parotid-specific transgene expression requires an upstream cis-regulatory domain, namely the parotid control region, which extends from -6 to -1.7 kb of the R15 gene; (2) this parotid control region functions with a heterologous promoter and is indispensable for achieving a reproducible chromosomal position-independent transgene expression; (3) deletion of the R15 5'-flanking region up to -1.7 kb results in a pleiotropic effect on the transgene expression, which includes ectopic (nonsalivary) reporter expression and lack of inducibility by either the beta-agonist isoproterenol or dietary tannin stimulation; (4) when the -10 to -6 kb region from the R15 gene is deleted in the construct, the inducible expression in the parotid glands of the transgenic mice decreases by over 30-fold, but position-independent and tissue-specific transgene expression is retained. Moreover, the mechanism of induction by either catecholamine isoproterenol or dietary tannin appears to be through a beta 1-adrenergic receptor-mediated pathway for both normal (non-transgenic) and transgenic animals.
Department of Pharmacology, University of Minnesota Medical School, Minneapolis 55455.
Z J
ZJ
Tu
K W
KW
Lazowski
R G
RG
Ehlenfeldt
G
G
Wu
H H
HH
Lin
E
E
Kousvelari
D K
DK
Ann
D000818:Animals; D005786:Gene Expression Regulation / Q000187:drug effects*; D047348:Hydrolyzable Tannins / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology*; D051379:Mice; D008822:Mice, Transgenic; D009928:Organ Specificity; D010306:Parotid Gland / Q000378:metabolism*; D010452:Peptide Biosynthesis; D010455:Peptides / Q000235:genetics*; D055232:Proline-Rich Protein Domains; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid
D047348:Hydrolyzable Tannins; D010455:Peptides; D011993:Recombinant Fusion Proteins; D011433:Propranolol; D007545:Isoproterenol