Regulation of Protein Synthesis in Ventricular Myocytes by Vasopressin

Reilly, Barbara; Brostrom, Margaret A.; Brostrom, Charles O.

doi:10.1074/jbc.273.6.3747

Cited by 37 publications

(27 citation statements)

References 45 publications

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“…8A, treatment of H9c2 cells with vasopressin resulted in a ϳ10 -12-fold increase in GATA-4 protein levels as early as 30 min following exposure to the hormone. The molecular chaperone BiP, a protein whose expression is known to be stimulated following vasopressin-induced hypertrophy (38,39), demonstrated increasing expression, while Cdk1 protein content was inhibited within 1 h of exposure consistent with hypertrophic reprogramming. Northern analysis of steady-state GATA-4 mRNA abundance demonstrated only a ϳ2-fold increase in transcript levels (Fig.…”

Section: Gata-4 Ires Activity Is Stimulated During Vasopressin-inducedmentioning

confidence: 94%

Protein Kinase C Regulates Internal Initiation of Translation of the GATA-4 mRNA following Vasopressin-induced Hypertrophy of Cardiac Myocytes

Sharma

Masri

et al. 2007

Journal of Biological Chemistry

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GATA-4 is a key member of the GATA family of transcription factors involved in cardiac development and growth as well as in cardiac hypertrophy and heart failure. Our previous studies suggest that GATA-4 protein synthesis may be translationally regulated. We report here that the 518-nt long 5-untranslated region (5-UTR) of the GATA-4 mRNA, which is predicted to form stable secondary structures (؊65 kcal/mol) such as to be inhibitory to cap-dependent initiation, confers efficient translation to monocistronic reporter mRNAs in cell-free extracts. Moreover, uncapped GATA-4 5-UTR containing monocistronic reporter mRNAs continue to be well translated while capped reporters are insensitive to the inhibition of initiation by cap-analog, suggesting a capindependent mechanism of initiation. Utilizing a dicistronic luciferase mRNA reporter containing the GATA-4 5-UTR within the intercistronic region, we demonstrate that this leader sequence confers functional internal ribosome entry site (IRES) activity. The activity of the GATA-4 IRES is unaffected in trans-differentiating P19CL6 cells, however, is strongly stimulated immediately following arginine-vasopressin exposure of H9c2 ventricular myocytes. IRES activity is then maintained at submaximal levels during hypertrophic growth of these cells. Supraphysiological Ca 2؉ levels diminished stimulation of IRES activity immediately following exposure to vasopressin and inhibition of protein kinase C activity utilizing a pseudosubstrate peptide sequence blocked IRES activity during hypertrophy. Thus, our data suggest a mechanism for GATA-4 protein synthesis under conditions of reduced global cap-dependent translation, which is maintained at a submaximal level during hypertrophic growth and point to the regulation of GATA-4 IRES activity by sarco(ER)-reticular Ca 2؉ stores and PKC.

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Section: Gata-4 Ires Activity Is Stimulated During Vasopressin-inducedmentioning

confidence: 94%

Protein Kinase C Regulates Internal Initiation of Translation of the GATA-4 mRNA following Vasopressin-induced Hypertrophy of Cardiac Myocytes

Sharma

Masri

et al. 2007

Journal of Biological Chemistry

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“…H9c2 myoblasts, derived from embryonic rat ventricle, were an excellent model system in which to directly test the effects of V 1A R signaling during in vitro stress, as they express cardiac and skeletal isoforms of L-type Ca 21 channels, sarcolemmal ATPase splice variants characteristic of a normal heart and endogenous V 1A R, which respond to AVP with typical Ga q protein-coupled receptor responses (Hescheler et al, 1991;Sipido and Marban, 1991;Hammes et al, 1994;Tran et al, 1995;Reilly et al, 1998;Chen and Chen, 1999;Guo et al, 2012). During the development of the H/R model, we initially found that H/R increased caspase 3/7 activity and decreased cell viability with enhanced robustness over normoxic conditions only under serum-free conditions, whereas the presence of fetal bovine serum protected the cells.…”

Section: Avp Protects H9c2mentioning

confidence: 99%

Arginine Vasopressin Enhances Cell Survival via a G Protein–Coupled Receptor Kinase 2/β-Arrestin1/Extracellular-Regulated Kinase 1/2–Dependent Pathway in H9c2 Cells

et al. 2013

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Circulating levels of arginine vasopressin (AVP) are elevated during hypovolemia and during cardiac stress. AVP activates arginine vasopressin type 1A (V 1A )/Ga q -coupled receptors in the heart and vasculature and V 2 /Ga s -coupled receptors in the kidney. However, little is known regarding the signaling pathways that influence the effects of V 1A receptor (V 1A R) activation during cellular injury. Using hypoxia-reoxygenation (H/R) as a cell injury model, we evaluated cell survival and caspase 3/7 activity in H9c2 myoblasts after treatment with AVP. Pretreatment of H9c2 cells with AVP significantly reduced H/R-induced cell death and caspase 3/7 activity, effects that were blocked via both selective V 1A R inhibition and mitogenactivated protein kinase (MEK1/2) inhibition. AVP increased extracellular-regulated kinase 1/2 (ERK1/2) phosphorylation in a concentration-dependent manner that was sensitive to MEK1/2 inhibition and V 1A R inhibition, but not V 1B R or V 2 R inhibition. Discrete elements of the V 1A /Ga q -protein kinase C (PKC) and V 1A /G protein-coupled receptor kinase (GRK)/b-arrestin signaling cascades were inhibited to dissect the pathways responsible for the protective effects of V 1A R signaling: Ga q (overexpression of Gq-I-ires-green fluorescent protein), PKC (administration of Ro 31-82425; 2-[8-(aminomethyl)-6,7,8,9-tetrahydropyrido[1,2-a]indol-3-yl]-3-(1-methyl-1H-indol-3-yl)maleimide, HCl, bisindolylmaleimide X, HCl), GRK2 [C-terminal GRK2 peptide overexpression and small interfering RNA (siRNA) knockdown], GRK5 (siRNA knockdown), and b-arrestin1 (siRNA knockdown). These studies demonstrated that both Ga q /PKC-and GRK2/b-arrestin1-dependent V 1A R signaling were capable of inducing ERK1/2 phosphorylation in response to AVP stimulation. However, AVP-mediated protection against H/R was elicited only via GRK2-and b-arrestin1-dependent signaling. These results suggest that activation of the V 1A R in H9c2 cells mediates protective signaling via a GRK2/b2 arrestin1/ERK1/2-dependent mechanism that leads to decreased caspase 3/7 activity and enhanced survival under conditions of ischemic stress.

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“…In the experiments shown in Figs. 5 and 6, [Ca 2ϩ ] i was directly manipulated by preincubation of 293T cells with ionomycin and 3 mM EGTA, followed either by incubation with ionomycin/2 mM Ca 2ϩ or by continued incubation with ionomycin/EGTA, essentially according to the protocol of Reilly et al (41). As shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…In addition, [Ca 2ϩ ] i -dependent phosphorylation of an elongation factor, eEF2 by a Ca 2ϩ /CaM-dependent protein kinase, elongation factor-2 kinase, is thought to reduce the rate of peptide chain elongation to the point where it becomes ratelimiting for overall rates of translation (62)(63)(64). The stimuli capable of mobilizing [Ca 2ϩ ] i and inhibiting translation, such as ionomycin, thapsigargin, or the excitotoxic glutamate receptor agonist N-methyl-D-aspartate (41,(63)(64)(65), evoke cellular stress responses that, if prolonged, lead to cell death, a process that may underly pathological conditions such as transient ischemia or neurodegenerative disease (reviewed in Ref. 66).…”

Section: Discussionmentioning

confidence: 99%

Phosphorylation Screening Identifies Translational Initiation Factor 4GII as an Intracellular Target of Ca2+/Calmodulin-dependent Protein Kinase I

Hui

Raught

Sonenberg

et al. 2003

Journal of Biological Chemistry

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CaMKI is a Ca 2؉/calmodulin-dependent protein kinase that is widely expressed in eukaryotic cells and tissues but for which few, if any, physiological substrates are known. We screened a human lung cDNA expression library for potential CaMKI substrates by solid phase in situ phosphorylation ("phosphorylation screening"). Multiple overlapping partial length cDNAs encoding three proteins were detected. Two of these proteins are known: 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase and eukaryotic translation initiation factor ( ] i -dependent, CaMKI site-specific, eIF4GII phosphorylation in vivo. This phosphorylation was blocked by kinase-negative CaMKI consistent with a requirement for endogenous CaMKI for in vivo eIF4GII phosphorylation. We conclude that phosphorylation screening is an effective method for searching for intracellular targets of CaMKI and may have identified a new role of Ca 2؉ signaling to the translation apparatus.

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Regulation of Protein Synthesis in Ventricular Myocytes by Vasopressin

Cited by 37 publications

References 45 publications

Protein Kinase C Regulates Internal Initiation of Translation of the GATA-4 mRNA following Vasopressin-induced Hypertrophy of Cardiac Myocytes

Protein Kinase C Regulates Internal Initiation of Translation of the GATA-4 mRNA following Vasopressin-induced Hypertrophy of Cardiac Myocytes

Arginine Vasopressin Enhances Cell Survival via a G Protein–Coupled Receptor Kinase 2/β-Arrestin1/Extracellular-Regulated Kinase 1/2–Dependent Pathway in H9c2 Cells

Phosphorylation Screening Identifies Translational Initiation Factor 4GII as an Intracellular Target of Ca2+/Calmodulin-dependent Protein Kinase I

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