The role of cytoskeletal microtubules and microfilaments in modulating cAMP generation in S49 lymphoma cells was investigated using the agents colchicine and cytochalasin B, respectively, which are known to disrupt these structures. A 1-hr pretreatment of S49 cells with 10 microM colchicine typically enhanced maximal isoproterenol-(beta-adrenergic receptor) stimulated cAMP accumulation by 100%,...

introduction: recent studies have shown that astrocytes play major roles in normal and disease condition of the central nervous system including multiple sclerosis (ms). molecular target therapy studies in ms have revealed that connexin-43 (cx43) and aquaporin-4 (aqp4) contents of astrocytes undergo expression alteration. fluoxetine had some effects in ms patients unrelated to its known antidep...

Lipid accumulation in pancreatic beta-cells is thought to cause its dysfunction and/or destruction via apoptosis. Our studies show that incubation of the beta-cell line RINm5F with the saturated free fatty acids (FFA) palmitate caused apoptosis based on increases in caspase 3 activity, Annexin V staining, and cell death. Furthermore, exposure of RINm5F cells to cAMP-increasing agents, 3-isobuty...

Synaptic plasticity in the central nervous system (CNS) of mammals has been discussed for many years. Several forms of synaptic plasticity of mammal’s CNS have been identified, such as those that occur in long-term potentiation (LTP). Different types of LTP have been observed in distinctive areas of the CNS of mammals. The hippocampus is one of the most important areas in the CNS that pla...

Agonist-mediated activation of the type 1 parathyroid hormone receptor (PTH1R) results in several signaling events and receptor endocytosis. It is well documented that arrestins contribute to desensitization of both G(s)- and G(q)-mediated signaling and mediate PTH1R internalization. However, whether PTH1R trafficking directly contributes to signaling remains unclear. To address this question, ...

Signaling by the metabotropic glutamate receptor 1a (mGluR1a) can lead to the accumulation of inositol 1,4,5-trisphosphate (InsP3) and cAMP and to the modulation of K1 and Ca21 channel opening. At present, very little is known about how these different actions are integrated and eventually turned off. Unraveling the molecular mechanisms underlying these functions is crucial for understanding mG...

The inner ear consists of two otocyst-derived, structurally and functionally distinct components: the dorsal vestibular and ventral auditory compartments. BMP signaling is required to form the vestibular compartment, but how it complements other required signaling molecules and acts intracellularly is unknown. Using spatially and temporally controlled delivery of signaling pathway regulators to...

Melanocortin-1 receptor (MC1R) and its ligands, alpha-melanocyte stimulating hormone (alphaMSH) and agouti signaling protein (ASIP), regulate switching between eumelanin and pheomelanin synthesis in melanocytes. Here we investigated biological effects and signaling pathways of ASIP. Melan-a non agouti (a/a) mouse melanocytes produce mainly eumelanin, but ASIP combined with phenylthiourea and ex...

Ustilago maydis, a pathogen of maize, is a useful model for the analysis of mating, pathogenicity, and the morphological transition between budding and filamentous growth in fungi. As in other fungi, these processes are regulated by conserved signaling mechanisms, including the cyclic AMP (cAMP)/protein kinase A (PKA) pathway and at least one mitogen-activated protein kinase (MAP kinase) pathwa...

Corticotropin-releasing factor (CRF) and vasoactive intestinal polypeptide (VIP) are neuropeptides displaying a variety of short-term effects in the nervous system. It is shown here in transfection experiments of an immortalized noradrenergic locus coeruleus-like cell line that both CRF and VIP also trigger a signaling cascade capable of activating gene transcription. To elucidate the signaling...