Edited by Roger J. ColbranTransient receptor potential canonical type 5 (TRPC5) is a Ca 2؉ -permeable cation channel that is highly expressed in the brain and is implicated in motor coordination, innate fear behavior, and seizure genesis. The channel is activated by a signal downstream of the G-protein-coupled receptor (GPCR)-G q/11 -phospholipase C (PLC) pathway. In this study we aimed to identify the molecular mechanisms involved in regulating TRPC5 activity. We report that Arg-593, a residue located in the E4 loop near the TRPC5 extracellular Gd 3؉ binding site, is critical for conferring the sensitivity to GPCR-G q/11 -PLC-dependent gating on TRPC5. Indeed, guanosine 5-O-(thiotriphosphate) and GPCR agonists only weakly activate the TRPC5 R593A mutant, whereas the addition of Gd 3؉ rescues the mutant's sensitivity to GPCR-G q/11 -PLC-dependent gating. Computer modeling suggests that Arg-593 may cross-bridge the E3 and E4 loops, forming the "molecular fulcrum." While validating the model using site-directed mutagenesis, we found that the Tyr-542 residue is critical for establishing a functional Gd 3؉ binding site, the Tyr-541 residue participates in fine-tuning Gd 3؉ -sensitivity, and that the Asn-584 residue determines Ca 2؉ permeability of the TRPC5 channel. This is the first report providing molecular insights into the molecular mechanisms regulating the sensitivity to GPCR-G q/11 -PLC-dependent gating of a receptor-operated channel.Transient receptor potential canonical type 5 (TRPC5) 2 channels are predominantly expressed in the nervous system. The highest levels of TRPC5 expression are found in mammalian brain regions such as the amygdala, hippocampus, cerebellum, cerebral cortex, and substantia nigra (1, 2). TRPC5 activation is implicated in regulating neurite outgrowth, growth cone morphology, and dendritic morphogenesis (3-5). In humans, TRPC5 gene mutations are associated with male mental retardation (2). TRPC5 knock-out mice exhibit deficits in motor coordination and innate fear behavior (6, 7). Genetic ablation of TRPC5 also reduces pilocarpine-induced seizures, long term potentiation, and seizure-induced neuronal cell death in the mouse hippocampus (8, 9). Plasma membrane insertion of TRPC5 in pyramidal hippocampal neurons is associated with the generation of prolonged cholinergic depolarization and bursting during epileptiform seizure discharges, suggesting that elevated TRPC5 activity may lead to an imbalance in hippocampal neuronal networks (10).Although TRPC5 channels have critical physiological roles, the molecular mechanisms involved in regulating TRPC5 activity remain not fully elucidated. TRPC5 proteins are localized to the plasma membrane and function as Na ϩ -and Ca 2ϩ -permeable channels. A TRPC5 channel consists of four subunits, each subunit containing six ␣-helical transmembrane domains (S1-S6, Fig. 1A) and a pore loop located between the S5 and S6 transmembrane domains (1, 11). The conduction pathway of the channel is formed by the S6 transmembrane domain and pore loop residues. Act...

Industrial activities have a detrimental impact on the environment and health when high concentrations of pollutants are released. Phytoremediation is a natural method of utilizing plants to remove contaminants from the soil. The goal of this study was to investigate the ability of Cannabis sativa L. to sustainably grow and remediate abandoned coal mine land soils in Pennsylvania. In this study, six different varieties of industrial hemp (Fedora 17, Felina 32, Ferimon, Futura 75, Santhica 27, and USO 31) were grown on two different contaminated soil types and two commercial soils (Miracle-Gro Potting Mix and PRO-MIX HP Mycorrhizae High Porosity Grower Mix). Plants growing in all soil types were exposed to two environmental conditions (outside and in the greenhouse). Seed germination response and plant height indicated no significant differences among all hemp varieties grown in different soils, however on an average, the height of the plants grown in the greenhouse exceeded that of the plants grown outdoors. In addition, heavy metal analysis of Arsenic, Lead, Nickel, Mercury, and Cadmium was performed. The concentration of Nickel was 2.54 times greater in the leaves of hemp grown in mine land soil outdoors when compared to greenhouse conditions. No differences were found between expression of heavy metal transporter genes. Secondary metabolite analysis of floral buds from hemp grown in mine land soil displayed a significant increase in the total Cannabidiol content (2.16%, 2.58%) when compared to Miracle-Gro control soil (1.08%, 1.6%) for outdoors and in the greenhouse, respectively. Molecular analysis using qRT-PCR indicated an 18-fold increase in the expression of the cannabidiolic acid synthase gene in plants grown on mine land soil. The data indicates a high tolerance to heavy metals as indicated from the physiological and metabolites analysis.

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Signaling networks that regulate cellular proliferation often involve complex interactions between several signaling pathways. In this manuscript we review the crosstalk between the Casein Kinase II (CK2) and Glycogen Synthase Kinase-3 (GSK-3) pathways that plays a critical role in the regulation of cellular proliferation in leukemia. Both CK2 and GSK-3 are potential targets for anti-leukemia treatment. Previously published data suggest that CK2 and GSK-3 act synergistically to promote the phosphatidylinositol-3 kinase (PI3K) pathway via phosphorylation of PTEN. More recent data demonstrate another mechanism through which CK2 promotes the PI3K pathway – via transcriptional regulation of PI3K pathway genes by the newly-discovered CK2-Ikaros axis. Together, these data suggest that the CK2 and GSK-3 pathways regulate AKT/PI3K signaling in leukemia via two complementary mechanisms: a) direct phosphorylation of PTEN and b) transcriptional regulation of PI3K-promoting genes. Functional interactions between CK2, Ikaros and GSK3 define a novel signaling network that regulates proliferation of leukemia cells. This regulatory network involves both direct posttranslational modifications (by CK and GSK-3) and transcriptional regulation (via CK2-mediated phosphorylation of Ikaros). This information provides a basis for the development of targeted therapy for leukemia.