Interactions Between the Inositol 1,4,5-Trisphosphate and Cyclic AMP Signaling Pathways Regulate Larval Molting in Drosophila

Genetics ◽  
2001 ◽  
Vol 158 (1) ◽  
pp. 309-318 ◽  
Author(s):  
K Venkatesh ◽  
G Siddhartha ◽  
Rohit Joshi ◽  
Sonal Patel ◽  
Gaiti Hasan
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Signaling Pathways ◽  
Feedback Inhibition ◽  
Receptor Gene ◽  
Dominant Negative ◽  
Neural Signals ◽  
Inositol 1,4,5 Trisphosphate ◽  
Kinase A ◽  
Insp3 Receptor

Abstract Larval molting in Drosophila, as in other insects, is initiated by the coordinated release of the steroid hormone ecdysone, in response to neural signals, at precise stages during development. In this study we have analyzed, using genetic and molecular methods, the roles played by two major signaling pathways in the regulation of larval molting in Drosophila. Previous studies have shown that mutants for the inositol 1,4,5-trisphosphate receptor gene (itpr) are larval lethals. In addition they exhibit delays in molting that can be rescued by exogenous feeding of 20-hydroxyecdysone. Here we show that mutants for adenylate cyclase (rut) synergize, during larval molting, with itpr mutant alleles, indicating that both cAMP and InsP3 signaling pathways function in this process. The two pathways act in parallel to affect molting, as judged by phenotypes obtained through expression of dominant negative and dominant active forms of protein kinase A (PKA) in tissues that normally express the InsP3 receptor. Furthermore, our studies predict the existence of feedback inhibition through protein kinase A on the InsP3 receptor by increased levels of 20-hydroxyecdysone.

scholarly journals Cooperative Activation of Lipolysis by Protein Kinase A and Protein Kinase C Pathways in 3T3-L1 Adipocytes

Endocrinology ◽  
2004 ◽  
Vol 145 (11) ◽  
pp. 4940-4947 ◽  
Author(s):  
Katrin Fricke ◽  
Aleksandra Heitland ◽  
Erik Maronde
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Signaling Pathways ◽  
Hormone Sensitive Lipase ◽  
Glycerol Release ◽  
Kinase C ◽  
Lipolytic Effect ◽  
Pka Pathway ◽  
Kinase A

Abstract In the present study, we investigate the coherence of signaling pathways leading to lipolysis in 3T3-L1 adipocytes. We observe two linear signaling pathways: one well known, acting via cAMP and protein kinase A (PKA) activation, and a second one induced by phorbol 12-myristate 13-acetate treatment involving protein kinase C (PKC) and MAPK. We demonstrate that both the PKA regulatory subunits RIα and RIIβ are expressed in 3T3-L1 adipocytes and are responsible for the lipolytic effect mediated via the cAMP/PKA pathway. Inhibition of the PKA pathway by the selective PKA inhibitor Rp-8-CPT-cAMPS does not impair lipolysis induced by PKC activation, and neither PD98059 nor U0126, as known MAPK kinase inhibitors, changes the level of glycerol release caused by PKA activation, indicating no cross-talk between these two pathways when only one is activated. However, when both are activated, they act synergistically on glycerol release. Additional experiments focusing on this synergy show no involvement of MAPK phosphorylation and cAMP formation. Phosphorylation of hormone-sensitive lipase is similar upon stimulation of either pathway, but we demonstrate a difference in the ability of both PKA and the PKC pathway activation to phosphorylate perilipin, which in turn may be an explanation for the different maximal lipolytic effect of both pathways.

Control of CCK gene transcription by PACAP in STC-1 cells

2000 ◽  
Vol 279 (3) ◽  
pp. G605-G612 ◽  
Author(s):  
Damian G. Deavall ◽  
Raktima Raychowdhury ◽  
Graham J. Dockray ◽  
Rod Dimaline
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Gene Transcription ◽  
Transcriptional Start Site ◽  
Dominant Negative ◽  
Activator Protein 1 ◽  
Mobility Shift ◽  
Creb Phosphorylation ◽  
Mobility Shift Assay ◽  
Kinase A

The mechanisms by which neuroendocrine stimulants regulate CCK gene transcription are unclear. We examined promoter activation by pituitary adenylate cyclase-activating polypeptide (PACAP), a known CCK secretagogue, in the enteroendocrine cell line STC-1. The promoter region from −70 to −87 bp, relative to the transcriptional start site, contains a composite calcium/cyclic AMP response element (CRE)/activator protein 1 (AP1) site that may bind CRE binding protein (CREB) and AP1. PACAP (with IBMX) stimulated expression of an 87-bp construct 3.35 ± 0.36-fold but had no effect on a −70 construct. The effect was blocked by the protein kinase A inhibitor H-89 and by a dominant-negative CREB plasmid. Mutation of the CRE/AP1 site to a canonical CRE site did not affect the response to PACAP, but mutation to a canonical AP1 site prevented it. CREB phosphorylation was increased after PACAP treatment. Electrophoretic mobility shift assay and supershift analysis revealed that CREB and not AP1 bound to the CRE/AP1 site and that PACAP increased the proportion of phosphorylated CREB that was bound. We conclude that PACAP increases CCK gene expression via a cAMP-mediated pathway involving CREB phosphorylation by protein kinase A and activation of a composite CRE/AP1 site.

scholarly journals Role of vaspin in porcine ovary: effect on signaling pathways and steroid synthesis via GRP78 receptor and protein kinase A†

2020 ◽  
Vol 102 (6) ◽  
pp. 1290-1305 ◽  
Author(s):  
Patrycja Kurowska ◽  
Ewa Mlyczyńska ◽  
Monika Dawid ◽  
Joelle Dupont ◽  
Agnieszka Rak
Keyword(s):  
Protein Kinase ◽  
Western Blot ◽  
Protein Kinase A ◽  
Signaling Pathways ◽  
Dependent Manner ◽  
Steroid Synthesis ◽  
Ovarian Cells ◽  
Vitro Effect ◽  
Kinase A

Abstract Vaspin, visceral-adipose-tissue-derived serine protease inhibitor, is involved in the development of obesity, insulin resistance, inflammation, and energy metabolism. Our previous study showed vaspin expression and its regulation in the ovary; however, the role of this adipokine in ovarian cells has never been studied. Here, we studied the in vitro effect of vaspin on various kinase-signaling pathways: mitogen-activated kinase (MAP3/1), serine/threonine kinase (AKT), signal transducer and activator of transcription 3 (STAT3) protein kinase AMP (PRKAA1), protein kinase A (PKA), and on expression of nuclear factor kappa B (NFKB2) as well as on steroid synthesis by porcine ovarian cells. By using western blot, we found that vaspin (1 ng/ml), in a time-dependent manner, increased phosphorylation of MAP3/1, AKT, STAT3, PRKAA1, and PKA, while it decreased the expression of NFKB2. We observed that vaspin, in a dose-dependent manner, increased the basal steroid hormone secretion (progesterone and estradiol), mRNA and protein expression of steroid enzymes using real-time PCR and western blot, respectively, and the mRNA of gonadotropins (FSHR, LHCGR) and steroids (PGR, ESR2) receptors. The stimulatory effect of vaspin on basal steroidogenesis was reversed when ovarian cells were cultured in the presence of a PKA pharmacological inhibitor (KT5720) and when GRP78 receptor was knocked down (siRNA). However, in the presence of insulin-like growth factor type 1 and gonadotropins, vaspin reduced steroidogenesis. Thus, vaspin, by activation of various signaling pathways and stimulation of basal steroid production via GRP78 receptor and PKA, could be a new regulator of porcine ovarian function.

scholarly journals Protein Kinase A Increases Type-2 Inositol 1,4,5-Trisphosphate Receptor Activity by Phosphorylation of Serine 937

2009 ◽  
Vol 284 (37) ◽  
pp. 25116-25125 ◽  
Author(s):  
Matthew J. Betzenhauser ◽  
Jenna L. Fike ◽  
Larry E. Wagner ◽  
David I. Yule
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Receptor Activity ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor ◽  
Kinase A

What is the Impact of Bisphenol A on Sperm Function and Related Signaling Pathways: A Mini-review?

2020 ◽  
Vol 26 (37) ◽  
pp. 4822-4828
Author(s):  
Yian Zhou ◽  
Wenqing Xu ◽  
Yuan Yuan ◽  
Tao Luo
Keyword(s):  
Protein Kinase ◽  
Animal Models ◽  
Bisphenol A ◽  
Protein Kinase A ◽  
Signaling Pathways ◽  
Male Reproduction ◽  
Sperm Function ◽  
Epigenetic Changes ◽  
The Impact ◽  
Kinase A

Bisphenol A (BPA) is an organic synthetic compound that is ubiquitously present in daily life. It is a typical environmental endocrine disruptor that affects the functions of endogenous hormones. There is a significant negative correlation between BPA and male reproduction. This mini-review describes current research data on the negative effects of BPA on sperm functions in humans and animal models, as well as on its supposed mechanisms of action, such as CATSPER-Ca2+ signaling, cAMP-protein kinase A signaling, and epigenetic changes. The published evidence showed an adverse impact of BPA on sperm tail morphology, counts, motility, and acrosome reaction action. Sperm function related signaling pathways, such as CATSPER-Ca2+ signaling, cAMP-protein kinase A signaling, and phosphorylation signaling, as well as epigenetic changes and sperm aging, are associated with BPA exposure in human and animal models. The clear risks of BPA exposure can provide greater awareness of the potential threat of environmental contaminants on male fertility.

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