Analysis offra-2 gene expression

Abstract

We have analyzed the transcriptional regulation of the fra-2 gene in chicken embryo fibroblasts. Like c-fos, fra-2 was inducible by phorbol ester, cAMP and calcium ionophore, as well as serum. In all three cases, the induction of two species of fra-2 transcript (5.7 kb and 6.8 kb) was delayed and prolonged compared with that of c-fos mRNA. The size difference between the two transcripts was attributable to the heterogeneity of the 3'-end, probably reflecting utilization of different polyadenylation sites. The major transcriptional start point is located at 30 bp downstream of a TATA-like sequence. In the fra-2 promoter region, which is located in a typical CpG island, enhancer consensus sequences such as SCM, SRE, GC boxes and CRE-like sequences were detected upstream of the TATA-like sequence in the same order as that in the 5'-upstream region of the chicken c-fos gene. Fibroblast transfection studies with a series of promoter deletion constructs positioned upstream of bacterial chloramphenicol acetyltransferase indicated, however, that SRE-like sequence is not the sole responsible element for the serum induction, and that a minimal fragment containing no SRE-like sequence is sufficient for this induction. Two typical AP-1 sequences are located between the major transcriptional initiation site and the coding sequence, and the binding activity of protein complexes to these sequences was induced by serum.

Cyclosporin A elicits dose-dependent biphasic effects on osteoblast differentiation and bone formation

“…Our results demonstrate that treatment with CsA and the specific inhibition of NFATc1 by siRNA increase the expression of Fra-2. Analysis of the fra-2 promoter [59] by a Transcription Element Search System (TESS) program [60] identified three potential NFAT consensus sequences. NFAT binding to these sites could be responsible for the negative regulation of fra-2 expression.…”

Tissue-Specific Transgenic Knockdown of Fos-Related Antigen 2 (Fra-2) Expression Mediated by Dominant Negative Fra-2

“…1A). The Fra-2 promoter represents a good candidate for a Fra-2 target in vivo because it contains two AP-1 sites that interact with a Fra-2-containing AP-1 complex (10,50). Based on in vitro evidence (28), these sites have been proposed to mediate an autoregulatory Fra-2 transcriptional loop.…”

“…First, fra-2 expression is turned on by second messengers, including cyclic AMP (cAMP) (1,37) and Ca 2ϩ (24). Second, the ensuing response is rather protracted (1,45), albeit less so than the one displayed by the fra-1 gene (50). Third, Fra-2 protein is modified extensively, primarily through extracellular signal-regulated kinase/mitogen-activated protein kinase (MAPK) phosphorylation (7,11,28,30).…”

Phosphorylation and high level expression of Fra-2 in v-src transformed cells: a pathway of activation of endogenous AP-1

“…Transfection e ciency was normalized on the basis of b-galactosidase activity (Gorman et al, 1982;Yoshida et al, 1993). The 14 C radioactivity in the spots on TLC plates was quantitated by an image analyser (Fuji BAS 2000).…”

“…By DNA sequence analysis of the fra-2 promoter region, enhancer consensus sequences such as SCM (sis conditioned medium response element, or SIE (sis inducible element)), SRE (serum response element), GC boxes and a CRE (cAMP response element)-like sequence were detected upstream of the TATA-like sequence in the same order as that in the 5'-upstream region of the chicken c-fos gene (Yoshida et al, 1993). Transient expression experiments in CEF using a series of promoter deletion constructs positioned upstream of the chloramphenicol acetyl transferase (CAT) reporter gene indicated that two typical AP-1 binding sequences, which are located between the major transcriptional initiation site and the coding sequence, and the CRE-like sequence are the major enhancers responsible for the fra-2 induction by serum (Sonobe et al, 1995).…”