Whereas the population of KAT1 is subject to regulated traffic to and from the plasma membrane, nothing is known about GORK, its distribution and traffic in vivo. We have used transformations with fluorescently-tagged GORK to explore its characteristics in tobacco epidermis selleck compound and Arabidopsis guard cells. These studies showed that GORK assembles in puncta that reversibly dissociated as a function of the external K+ concentration. Puncta dissociation parallelled the gating dependence of GORK, the speed of response
consistent with the rapidity of channel gating response to changes in the external ionic conditions. Dissociation was also suppressed by the K+ channel blocker Ba2+. By contrast, confocal and protein biochemical analysis failed to uncover substantial exo- and endocytotic traffic of the channel. Gating of GORK is displaced to more positive voltages with external K+, a characteristic that ensures the channel facilitates only K+ efflux regardless of the external cation concentration. GORK conductance is also enhanced by external K+ above 1mm. We suggest that GORK clustering in puncta is related to its gating and conductance, and reflects associated conformational changes and (de)stabilisation of the channel
protein, possibly as a platform for transmission and coordination of channel gating in response to external selleck chemical K+.”
“Leptoglossus occidentalis Heidemann (Heteroptera, Coreidae), the western conifer seed bug, is a serious conifer seed pest in North America; after its accidental introduction in Italy, it has spread to several European countries. In Central Italy, severe seed loss was recorded in stone pine forests
(Pinus pinea). Classical biological control against L. occidentalis was evaluated by performing laboratory tests on Gryon pennsylvanicum (Ashmead), the most important hymenopteran egg parasitoid of the pest in North America, to acquire biological and demographical MI-503 mouse parameters. Tests were performed in climatic chambers using glass tubes to house specimens at 26 +/- 1 degrees C, 75 +/- 5% RH and 16:8 L:D and supplying honey drops as food for adults. G. pennsylvanicum reared on eggs of L. occidentalis has a high fecundity rate (144.55 eggs/female) and 90% of the total number of eggs are laid in the first two weeks of oviposition. Mean oviposition period is 23 days. Parasitoid females live a mean of 40 days, and longevity is higher in host deprived females. The intrinsic rate of increase (r(m)) was calculated to be 0.206. Mean sex ratio throughout a female’s life span was 70.42% females, though at the start of oviposition it was over 87% females. Adults survived only four days without honey as food, but up to 50 days with food; water did not influence longevity. Females lived significantly longer than males.