HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 290/2/F456    most recent 00009.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Zamorano, R. Articles by Gainer, J. V. Search for Related Content PubMed PubMed Citation Articles by Zamorano, R. Articles by Gainer, J. V.

3'-Untranslated region of the type 2 bradykinin receptor is a potent regulator of gene expression

Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee

Submitted 12 January 2005 ; accepted in final form 31 August 2005

Regulation of the constitutively expressed type 2 bradykinin (B₂) receptor, which mediates the principal actions of bradykinin, occurs at multiple levels. The goal of the current study was to determine whether the human B₂ 3'-untranslated region (UTR) has effects on gene expression, with particular focus on the variable number of tandem repeats (B₂-VNTR) polymorphic portion of the 3'-UTR and its flanking AU-rich elements (AREs). When inserted downstream of the luciferase coding region of the pGL3-Promoter vector, the B₂-VNTR reduced reporter gene activity by 85% compared with pGL3-Promoter alone (promoter control; P < 0.001), an effect that was not appreciably affected by mutation of the flanking AREs. The negative regulatory effects of the B₂-VNTR region were position and orientation dependent and strongly positively correlated with the number of tandem repeats in the B₂-VNTR region (r = 0.85, P < 0.001). With respect to mechanism, quantitative RT-PCR revealed that the B₂-VNTR mRNA level was 32% of that of promoter control (P = 0.008), whereas the number of polyadenylated transcripts was 4% (P = 0.02). In contrast, the mRNA half-life of the B₂-VNTR was increased (B₂-VNTR: 14.9 vs. promoter control: 12.2 h, P = 0.009). Transient transfection of human kidney-derived tsA201 cells with the B₂-VNTR construct increased transcription of the native B₂ receptor mRNA by 43% (P < 0.05), supporting an endogenous B₂ receptor-regulatory capacity of the B₂-VNTR. In conclusion, these results identify novel pretranslational effects of the B₂-VNTR region to act as a potent negative regulator of heterologous gene expression and support the notion that the bradykinin B₂ 3'-UTR may impact endogenous receptor regulation.

gene regulation; variable number of tandem repeats; polymorphism