Premium
Transcription of the β 2 ‐adrenergic receptor gene in rat liver is regulated during early postnatal development by an upstream repressor element
Author(s) -
Baeyens Dennis A.,
McGraw Dennis W.,
Jacobi Sandie E.,
Cornett Lawrence E.
Publication year - 1998
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/(sici)1097-4652(199806)175:3<333::aid-jcp11>3.0.co;2-6
Subject(s) - biology , transfection , reporter gene , fusion gene , microbiology and biotechnology , gene , gene expression , repressor , receptor , luciferase , liver receptor homolog 1 , adrenergic receptor , 5' flanking region , regulation of gene expression , transcription (linguistics) , transcription factor , promoter , nuclear receptor , genetics , linguistics , philosophy
As early postnatal development of the male rat proceeds, there is a decline in transcription of the β 2 ‐adrenergic receptor gene in liver which is associated with a decline in β 2 ‐adrenergic receptor mediated glucose mobilization. In this study, primary cultures of rat hepatocytes transiently transfected with fusion genes containing various segments of β 2 ‐adrenergic receptor gene 5′‐flanking DNA fused to a promoterless luciferase reporter gene were used to identify genetic elements that might control β 2 ‐adrenergic receptor gene expression during the first 10 days of postnatal life. We found that 261 bp of β 2 ‐adrenergic receptor gene 5′‐flanking region (−372 to −95, start of translation is +1) was sufficient to direct high luciferase expression in fetal day 18 hepatocytes and therefore included the β 2 ‐adrenergic receptor gene promoter. Luciferase activities in fetal day 18 hepatocytes transfected with pβ 2 AR(−372/−95), pβ 2 AR(−1,335/−95) and pβ 2 AR‐(−3,349/−95) were fourfold greater than that in either postnatal day 5 or postnatal day 10 hepatocytes transfected with the same fusion genes. By use of gel mobility shift assays, we observed increased protein binding to a 50 bp segment (−372 to −323) of the β 2 ‐adrenergic receptor gene 5′‐flanking region with nuclear extracts prepared from postnatal day 5 and postnatal day 10 hepatocytes compared to fetal day 18 hepatocytes. These findings suggest the presence of a regulatory element in the 5′‐flanking region of the β 2 ‐adrenergic receptor gene that appears to be involved in suppression of transcription of the β 2 ‐adrenergic receptor gene in liver during early postnatal development. J. Cell. Physiol. 175:333–340, 1998. © 1998 Wiley‐Liss, Inc.