The ppb1؉ gene encodes a fission yeast homologue of the mammalian calcineurin. We have recently shown that Ppb1 is essential for chloride ion homeostasis, and acts antagonistically with Pmk1 mitogen-activated protein kinase pathway. In an attempt to identify genes that share an essential function with calcineurin, we screened for mutations that confer sensitivity to the calcineurin inhibitor FK506 and high temperature, and isolated a mutant, its3-1. its3؉ was shown to be an essential gene encoding a functional homologue of phosphatidylinositol-4-phosphate 5-kinase (PI(4)P5K). The temperature upshift or addition of FK506 induced marked disorganization of actin patches and dramatic increase in the frequency of septation in the its3-1 mutants but not in the wild-type cells. Expression of a green fluorescent protein-tagged Its3 and the phospholipase C␦ pleckstrin homology domain indicated plasma membrane localization of PI(4)P5K and phosphatidylinositol 4,5-bisphosphate. These green fluorescent proteintagged proteins were concentrated at the septum of dividing cells, and the mutant Its3 was no longer localized to the plasma membrane. These data suggest that fission yeast PI(4)P5K Its3 functions coordinately with calcineurin and plays a key role in cytokinesis, and that the plasma membrane localization of Its3 is the crucial event in cytokinesis.Calcineurin, Ca 2ϩ /calmodulin-dependent protein phosphatase, is a molecular target for the specific immunosuppressive drugs, such as cyclosporin A or tacrolimus (FK506), 1 used in organ transplantation. These drugs induce their biological effects by forming an initial complex with cytosolic proteins termed immunophilins. These drug-immunophilin complexes then bind to and inhibit calcineurin (1). Calcineurin is widely distributed in mammalian tissues, and may have additional functions other than its well characterized role in lymphocytes. The inhibition of these functions may contribute to the side effects of these drugs. A better understanding of the biological roles of calcineurin in different cell types should promote the development of improved strategies for immunosuppression.Calcineurin is conserved from yeast to man (2-4). We have been studying calcineurin signal transduction pathways in fission yeast Schizosaccharomyces pombe because this system is amenable to genetics and has many advantages in terms of relevance to higher systems. S. pombe has a single gene encoding the catalytic subunit of calcineurin, ppb1 ϩ , that is essential for cytokinesis (4, 5). We have previously shown that ppb1 ϩ plays an essential role in maintaining chloride ion homeostasis, and acts antagonistically with Pmk1 mitogen-activated protein kinase pathway (6 -8). To identify new components in the calcineurin signaling pathway, we have developed a simple genetic screen using the immunosuppressive drug FK506 for mutants that depend on calcineurin for growth, and have identified eight complementation groups (its1-8 for immunosuppressant-and temperature-sensitive, to be described elsewhere in det...
Herein, an unprecedented switching of circularly polarized luminescence (CPL) is described for chiral 4,6-bis(1-(pyren-1-ylamino)propyl)dibenzo[b,d]furan (1). The CPL band of chiral diamine 1, which contains two pyrene rings, can be switched between the monomer and excimer emission regions under concomitant inversion of the handedness, simply by changing the concentration of the fluorophore. In contrast, the maximum photoluminescence (PL) intensity is always observed in the monomer region, regardless of the concentration. The reversal of the intensity ratio of monomer and excimer emission between PL and CPL was attributed to a stronger CPL (|g| = ∼3-4 × 10) contribution from the minor excimer component, which should exhibit an efficient chiral environment around the dimeric pyrenes.
Red- and blue-shifted mechanochromic luminescence (MCL) and single-particle level observation of tricolor MCL of phenanthroimidazolylbenzothiadiazoles are described.
The purpose of this study was to determine any discrepancies in the outputs of five commercial dental radiometers and also to evaluate the accuracy of these devices using a laboratory-grade spectroradiometer. The power densities of 12 different curing light sources were repeatedly measured for a total of five times using each radiometer in a random order. The emission spectra of all of the curing light sources were also measured using the spectroradiometer, and the integral value of each spectrum was calculated to determine the genuine power densities, which were then compared to the displayed power densities measured by the dental radiometers. The displayed values of power density were various and were dependent on the brand of radiometer, and this may be because each radiometer has a different wavelength sensitivity. These results cast doubt upon the accuracy of commercially available dental radiometers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.