Cyclic Amp Signaling and Gene Regulation

Abstract

Cyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger produced in cells in response to hormones and nutrients. The production of cAMP is dependent upon the actions of many different proteins that affect its synthesis and degradation. An important function of cAMP is to activate the phosphorylating enzyme, protein kinase A. The key roles of cAMP and protein kinase A in the phosphorylation and regulation of enzyme substrates involved in intermediary metabolism are well known. A newly discovered role for protein kinase A is in the phosphorylation and activation of transcription factors that are critical for the control of the transcription of genes in response to elevated levels of cAMP.

In vitro studies on the effect of 8-(4-chlorophenylthio) cAMP on selected biochemical parameters in Sertoli cells isolated from testis of transgenic mice

“…It exerts its effects by activating the cAMP-dependent protein kinaseA (PKA), which transduces the signal through phosphorylation of different target proteins. In the present study, cAMP exposure showed a significant decrease in the total protein levels in Sertoli cells isolated from testis of transgenic and normal mice, indicating cAMPinduced regulatory effects on transcription or translation and/or both [17]. The other biochemical variable lactate plays a vital role in energy homeostasis by acting as ATP producing moieties during mitochondrial oxidative phosphorylation.…”

Shear stress stimulates phosphorylation of protein kinase A substrate proteins including endothelial nitric oxide synthase in endothelial cells

“…To examine whether PKA is stimulated by shear stress, I first explored the phosphorylation of CREB, one of the well known regulatory targets of PKA (Daniel et al, 1998;Park et al, 2003;Min et al, 2004). When the BAECs were exposed to shear stress, there was a significant increase in CREB phosphorylation at Ser133, maximizing at 30 min from the onset of shear stress ( Figure 1A).…”

Identification of genes targeted by the androgen and PKA signaling pathways in prostate cancer cells

“…The catalytic subunits then dissociate and become active. The free catalytic subunit can phosphorylate serine and threonine residues; its entrance into the cell nucleus and subsequent phosphorylation of transcription factors -for example, CREB, CREM, NF-kB and nuclear receptors -forms the basis of PKA regulation of transcriptional activation (Daniel et al, 1998). However, FSK can also interact with other proteins such as glucose transporters which may influence gene expression (Morris et al, 1991).…”