Vertebrate oocytes arrest at prophase of meiosis I as a result of high levels of cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) activity. In Xenopus, progesterone is believed to release meiotic arrest by inhibiting adenylate cyclase, lowering cAMP levels and repressing PKA. However, the exact timing and extent of the cAMP decrease is unclear, with conflicting reports in the li...

Several studies have shown that magnesium can be a useful tool in preventing various skin disorders. However, the mechanism remains unclear. In this study, we analyzed by which improves function, focusing on water channel aquaporin-3 (AQP3), is cutaneous functional molecule. Magnesium compounds (magnesium acetate, chloride, sulfate, and lactate) were added to human epidermal keratinocyte HaCaT ...

Developmental control of cell proliferation is crucial, and abnormal principal cell proliferation may contribute to cystogenesis in polycystic kidney disease. This study investigates roles of cAMP and its primary effector, cAMP-dependent protein kinase (protein kinase A; PKA), in control of cell proliferation in filter-grown noncystic (NC) and cystic (CY)-derived principal cell cultures. These ...

Luteinizing hormone mediates its nuclear action primarily by activating cAMP/Protein kinase A (PKA) pathway leading to phosphorylation of cAMP response element binding (CREB) family of transcription factors. Earlier studies have documented altered cAMP responsiveness of luteal cells during maturation, and in the rhesus monkey, extinction of CREB expression following luteinization and ovulation....

Protein kinase A is a key mediator of cAMP signalling downstream of G-protein-coupled receptors, a signalling pathway conserved in all eukaryotes. cAMP binding to the regulatory subunits (PKAR) relieves their inhibition of the catalytic subunits (PKAC). Here we report that ARHGAP36 combines two distinct inhibitory mechanisms to antagonise PKA signalling. First, it blocks PKAC activity via a pse...

The glycoprotein hormones, ACTH, TSH, FSH, and LH regulate diverse functions in endocrine cells. Although cAMP and PKA have long been shown to mediate specific intracellular signaling events including the transcription of specific genes via the CREB-CBP complex, recent observations have indicated that PKA does not account for all of the intracellular targets of cAMP. For example, TSH stimulatio...

cAMP inhibits biochemical events leading to T cell activation by triggering of an inhibitory protein kinase A (PKA)-C-terminal Src kinase pathway assembled in lipid rafts. In this study, we demonstrate that activation of PKA type I by Sp-8-bromo-cAMPS (a cAMP agonist) has profound inhibitory effects on Ag-specific immune responses in peripheral effector T cells. Activation of PKA type I inhibit...

Expression of matrix metalloproteinase-1 (MMP-1) is stimulated by diverse stimuli and is likely to be regulated by many signaling pathways. cAMP is known to act as a second messenger for various extracellular stimuli and to be involved in the regulation of cell proliferation, apoptosis, and inflammation. Here, we investigated the effect of cAMP on tumor necrosis factor (TNF)-alpha-induced MMP-1...

Experiments in cultured endothelial cell monolayers demonstrate that increased intracellular cAMP strongly inhibits the acute permeability responses by both protein kinase A (PKA)-dependent and -independent pathways. The contribution of the PKA-independent pathways to the anti-inflammatory mechanisms of cAMP in intact mammalian microvessels has not been systematically investigated. We evaluated...

Glioma is the most common malignant cancer affecting the central nerve system, with dismal prognosis. Differentiation-inducing therapy is a novel strategy that has been preliminarily proved effective against malignant glioma. We have reported previously that activation of cAMP/protein kinase A (PKA) pathway is capable of inducing glioma cell differentiation, characterized by astrocyte-like shap...