Induction of proto-oncogene fos transcription through the adenylate cyclase pathway: characterization of a cAMP-responsive element.

Abstract

Transcription of proto-oncogene los is induced by elevated levels of intracellular cAMP. We report that human c-fos promoter recombinants transfected into rat pheochromocytoma cells (PC12) and human choriocarcinoma cells {JEG-3) are induced by stimulation of adenylate cyclase and that this induction is diminished considerably in the mutant PC12 cell line A126-1B2, which is deficient in cAMP-dependent protein kinase II. An element centered at position -60 of the c-los promoter, which encompasses a consensus cAMP response element (CRE), is sufficient to confer cAMP responsiveness to a herpes thymidine kinase/CAT fusion gene. The specific binding of a nuclear protein to the c-los CRE can be competed by the somatostatin and ~-chorionic gonadotropin {a-CG} promoter regions that contain CREs. Gel mobility shift assays with double-stranded oligonucleotides containing either the wild-type or mutated c-los CRE sequence have demonstrated that binding occurs only to the wild-type CRE. The nuclear factor binding to the c-los CRE is likely to be transcription factor CREB (CRE nuclear binding protein), because an affinity-purified 43-kD CREB isolated from PC12 cells binds efficiently in a DNA footprinting assay. Thus, regulation of the c-los gene transcription appears to involve a mechanism common to many genes that respond to cAMP as a second message leading to cell growth and differentiation.

Activation of the c-fos enhancer by the Erk MAP kinase pathway through two sequence elements: the c-fos AP-1 and p62TCF sites

“…However, these reporter genes contained over 200 nucleotides of the c-fos promoter including the CRE site at 760. The e ect of the FAP1 site observed here is likely because it was assayed without the 760 CRE which also binds ATF1 and CREB (Ginty et al, 1994;Sassone-Corsi et al, 1988) and because the e ect is clearer in conjunction with mutation of the TCF site. The role of the FAP1 site has most dramatically been shown in transgenic mouse with fos-lacZ constructs (Robertson et al, 1995).…”

“…The CRE can mediate cAMP and calcium induction in certain cell types but may also contribute to growth factor induction (Berkowitz et al, 1989;Fisch et al, 1989;Sassone-Corsi et al, 1988;Sheng et al, 1990). The CRE is bound by CREB and the related transcription factor ATF1 (Ginty et al, 1994;Montminy, 1997;Sassone-Corsi et al, 1988). Each is phosphorylated on a conserved serine (amino acid 133 in CREB and 63 in ATF1) that causes activation of the factors (Gonzalez and Montminy, 1989;Rehfuss et al, 1991).…”

Direct imaging of phosphorylation‐dependent conformational change and DNA binding of CREB by electron microscopy

“…Gel retardation assay was performed by a modi®ed method of Sassone-Corsi et al (1988). CREB was incubated for binding with a synthesized CRE oligonucleotide (Pharmacia) endlabelled with 32 P in the binding buffer (10 mM HEPES (pH 8.0), 50 mM KCl, and 0.5 mM DTT).…”

Cross-talk in signal transduction: Ras-dependent induction of cAMP-responsive transcriptional repressor ICER by nerve growth factor

“…Sassone-Corsi et al, 1988) containing upstream sequences up to position 7404. Coexpression of ICER resulted in a substantial repression of both cAMP and NGF-induced expression, while no e ect is observed in control transfections using vectors encoding an antisense ICER transcript (Figure 7).…”