Reactive Oxygen Species Decrease cAMP Response Element Binding Protein Expression in Cardiomyocytes via a Protein Kinase D1-Dependent Mechanism That Does Not Require Ser¹³³ Phosphorylation

Abstract

Reactive oxygen species (ROS) exert pleiotropic effects on a wide array of signaling proteins that regulate cellular growth and apoptosis. This study shows that long-term treatment with a low concentration of H 2 O 2 leads to the activation of signaling pathways involving extracellular signal-regulated kinase, ribosomal protein S6 kinase, and protein kinase D (PKD) that increase cAMP binding response element protein (CREB) phosphorylation at Ser 133 in cardiomyocytes. Although CREBSer 133 phosphorylation typically mediates cAMP-dependent increases in CREB target gene expression, the H 2 O 2 -dependent increase in CREB-Ser 133 phosphorylation is accompanied by a decrease in CREB protein abundance and no change in Creluciferase reporter activity. Mutagenesis studies indicate that H 2 O 2 decreases CREB protein abundance via a mechanism that does not require CREB-Ser 133 phosphorylation. Rather, the H 2 O 2 -dependent decrease in CREB protein is prevented by the proteasome inhibitor lactacystin, by inhibitors of mitogenactivated protein kinase kinase or protein kinase C activity, or by adenoviral-mediated delivery of a small interfering RNA that decreases PKD1 expression. A PKD1-dependent mechanism that links oxidative stress to decreased CREB protein abundance is predicted to contribute to the pathogenesis of heart failure by influencing cardiac growth and apoptosis responses.CREB is a bZip transcription factor that binds to specific DNA elements (termed cAMP-response elements or CREs) within the regulatory regions of CREB target genes; many genes with CREs in their promoters play key roles in cellular proliferation and apoptosis pathways. CREB is regulated via phosphorylation at Ser 133 , a modification variably attributed to protein kinase A (PKA), calcium/calmodulin-dependent kinase, p90 kDa ribosomal S6 kinase (RSK, an effector of the ERK-mitogen-activated protein kinase pathway), mitogenand stress-activated protein kinase 1, protein kinase D (PKD), or AKT (depending upon the cell type or inciting stimulus) (Johannessen et al., 2004). CREB-Ser 133 phosphorylation increases CREB-dependent gene transcription at least in part by recruiting coactivators (CREB binding protein or CBP) to the promoters of CREB target genes. In the heart, CREB is implicated in the maintenance of normal ventricular structure and function (Fentzke et al., 1998). CREB protein expression decreases in a pacing-induced cardiac memory model in dogs that is characterized by a specialized form of electrical remodeling involving alterations in the T-wave morphology during sinus rhythm (Patberg, 2005). There is recent evidence that pacing protocols that induce cardiac memory lead to enhanced tissue markers of oxidative stress (Ö zgen et al., 2007). It is tempting to speculate that this increase in ROS mediates the pacing-induced decrease CREB protein expression in cardiomyocytes, because oxidative stress decreases CREB protein abundance, depresses These studies were supported by United States Public Health Service and National Institutes...

The p38 MAPK-regulated PKD1/CREB/Bcl-2 pathway contributes to selenite-induced colorectal cancer cell apoptosis in vitro and in vivo

“…Moreover, studies with CRC cells treated with selenite combined with CID 755673 (PKD1 inhibitor) or PMA (PKD1 activator) indicated that the PKD1-mediated phosphorylation of p-CREB required the kinase activity of PKD1. However, a previous report indicated that the H2O2-induced inhibition of CREB via a PKD1-dependent mechanism did not require Ser133 phosphorylation [35]. To determine whether PKD1 phosphorylates CREB directly or indirectly in CRC cells, we performed co-immunoprecipitation and immunofluorescence experiments.…”

The C-terminus of the long AKAP13 isoform (AKAP-Lbc) is critical for development of compensatory cardiac hypertrophy

“…Under pathological conditions, PKD1 plays a key role in altered gene expression, hypertrophy and cardiac remodeling underlying heart failure [26] [29]. PKD1 also functions to regulate Ca 2+ -handling [46-48], sarcomeric dynamics and cardiac contractility [49] [50], and may play a cardioprotective role under conditions of oxidative stress [51-54]. Despite identification of these vital cardiac functions, it is not well understood how PKD1 is regulated in the heart [55], which is vital for understanding and treatment of cardiac disease.…”

Emergency Spatiotemporal Shift: The Response of Protein Kinase D to Stress Signals in the Cardiovascular System

“…Here activation of PKD by Gq leads to CREB serine 133 phosphorylation and the induction of CRE-responsive genes such as Bcl-2 contributing to cell survival (Ozgen et al, 2008). Low levels of oxidative stress also promote CREB phosphorylation, but this is associated with decreased CREB abundance and no change CREB target gene transcription (Ozgen et al, 2009). The importance of PKD-dependent CREB phosphorylation in cardiac remodeling processes is still unclear.…”