Temperature reducing coating for metals subject to flame exposure Patent

Anodizing method for providing metal surfaces with temperature reducing coatings against flame

Activation of phospholipase C beta 2 by the alpha and beta gamma subunits of trimeric GTP-binding protein

Cotransfection assays were used to show that the members of the GTP-binding protein Gq class of alpha subunits could activate phospholipase C (PLC) beta 2. Similar experiments also demonstrated that G beta 1 gamma 1, G beta 1 gamma 5, and G beta 2 gamma 5 could activate the beta 2 isoform of PLC but not the beta 1 isoform, while G beta 2 gamma 1 did not activate PLC beta 2. To determine which portions of PLC beta 2 are required for activation by G beta gamma or G alpha, a number of PLC beta 2 deletion mutants and chimeras composed of various portions of PLC beta 1 and PLC beta 2 were prepared. We identified the N-terminal segment of PLC beta 2 with amino acid sequence extending to the end of the Y box as the region required for activation by G beta gamma and the C-terminal region as the segment containing amino acid sequences required for activation by G alpha. Furthermore, we found that coexpression of G alpha 16 and G beta 1 gamma 1 but not G beta 1 gamma 5 in COS-7 cells was able to synergistically activate recombinant PLC beta 2. We suggest that G alpha 16 may act together with free G beta 1 gamma 1 to activate PLC beta 2, while G alpha 16 may form heterotrimeric complexes with G beta 1 gamma 5 and be stabilized in an inactive form. We conclude that the regions of PLC beta 2 required for activation by G beta gamma and G alpha are physically separate and that the nature of the G beta subunit may play a role in determining the relative specificity of the G beta gamma complex for effector activation while the nature of the G gamma subunit isoform may be important for determining the affinity of the G beta gamma complex for specific G alpha proteins

The G alpha q and G alpha 11 proteins couple the thyrotropin-releasing hormone receptor to phospholipase C in GH3 rat pituitary cells

Thyrotropin-releasing hormone stimulates the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) in GH3 cell membranes. The stimulation of the phosphoinositide phospholipase C (PI/PLC) activity can be blocked by incubation of GH3 membranes with polyclonal antibodies directed against a peptide derived from the C-terminal region of G alpha q and G alpha 11. Antibodies directed against the C- terminal region of other G alpha-subunits had no detectable effect. The inhibition was specific since addition of the peptide that was used to prepare the antibody completely reversed the inhibition. Further evidence for the coupling of the TRH receptor to G alpha q or G alpha 11 comes from a reconstitution experiment in which human embryonic kidney cells were transiently transfected with cDNAs corresponding to the TRH receptor, G alpha q or G alpha 11. The PIP2 hydrolysis detected with membranes from cells that over-expressed the TRH receptor alone was low, however, co-expression with the G alpha q or G alpha 11 subunits produced a synergistic stimulation of PI-PLC activity. In contrast, co-expression of these alpha-subunits with the M2 muscarinic acetylcholine receptor induced a weak stimulation of PIP2 hydrolysis. The results presented here suggest that the TRH-dependent stimulation of PI-PLC in GH3 cells is mediated through the G-protein alpha- subunits, G alpha q and/or G alpha 11

A segment of the C-terminal half of the G-protein .31 subunit specifies its interaction with the γ4 subunit

The β and γ subunits of the heterotrimeric guanine nucleotide binding (G protein) act as a dimer and directly regulate various signal transduction pathways. By using cotransfection assays, we tested the ability of several βγ combinations to activate inositol phospholipid-specific phospholipase C (PI-PLC)-β2. Our findings indicate that only βγ combinations that form dimers will activate PI-PLC-beta 2. Since G beta 1 interacts with Gγ1, while G beta 2 cannot, chimeras between Gβ1 and Gβ2 were used to identify the regions in beta 1 that determine its specific association with γ1. Our evidence demonstrates that a chimera between β2 and β1 that contains the C-terminal 173 amino acids of beta 1 can interact and activate PI-PLC-β2 with γ1. Chimeras that contain portions of the β1 C-terminal region display a weaker association with γ1. Furthermore, the contribution of each of these regions depends on the sequence context of each chimeric protein. However, the segment between residues 210 and 293 of β1 consistently plays a critical role in specifying association with γ1

Research Software Engineering in 2030

This position paper for an invited talk on the "Future of eScience" discusses the Research Software Engineering Movement and where it might be in 2030. Because of the authors' experiences, it is aimed globally but with examples that focus on the United States and United Kingdom.Comment: Invited paper for 2023 IEEE Conference on eScienc

Sound effect metaphors for near field distance sonification

International audienceThis article presents a concept of distance sound source sonification for virtual auditory displays in the context of the creation of an assistive device for the visually impaired. In order to respond to user needs, three sonification metaphors of distance based on sound effects were designed. These metaphors can be applied to any type of sound and thereby satisfy all aesthetic desires of users. The paper describes the motivation to use this new type of sonification based on sound effects, and proposes guidelines for the creation of these three metaphors. It then presents a user evaluation of these metaphors by 16 subjects through a near field sound localization experiment. The experiment included a simple binaural rendering condition in order to compare and quantify the contribution of each metaphor on the distance perception

Toroidal Perturbations of Friedmann-Robertson-Walker Universes

Explicit expressions are found for the axisymmetric metric perturbations of the closed, flat and open FRW universes caused by toroidal motions of the cosmic fluid. The perturbations are decomposed in vector spherical harmonics on 2-spheres, but the radial dependence is left general. Solutions for general odd-parity $l$-pole perturbations are given for either angular velocities or angular momenta prescribed. In particular, in case of closed universes the solutions require a special treatment of the Legendre equation.Comment: 13 page

Critical stance within a community of inquiry in an advanced mathematics course for pre-service teachers

publishedVersio

Functional Analysis of a Dominant Negative Mutant of Gαi2

The key event in receptor-catalyzed activation of heterotrimeric G proteins is binding of GTP, which leads to subunit dissociation generating GTP-bound alpha subunits and free beta complexes. We have previously identified a mutation that abolished GTP binding in Galpha(o) (S47C) and demonstrated that the mutant retained the ability to bind beta and could act in a dominant negative fashion when expressed in Xenopus oocytes (Slepak, V. Z., Quick, M. W., Aragay, A. M., Davidson, N., Lester, H. A., and Simon, M. I.(1993) J. Biol. Chem. 268, 21889-21894). In the current work, we investigated the effects of the homologous mutant of Galpha (S48C) upon signaling pathways reconstituted in transiently transfected COS-7 cells. We found that expression of the Galpha S48C mutant prevented stimulation of phospholipase C (PLC) beta2 by free beta subunit complexes. This effect of Galpha(i) S48C was not readily reversible in contrast to the inhibitory effect of wild-type Galpha, which could be reversed upon activation of the cotransfected muscarinic M2 receptor, presumably by release of beta from the G protein heterotrimer. Coexpression of Galpha(i) S48C or the wild-type Galpha also dramatically decreased G-mediated stimulation of PLC by C5a in the cells transfected with cDNAs encoding C5a receptor and Galpha. Activation of PLC via endogenous G(q) or G in the presence of alpha1C adrenergic receptors was similarly attenuated by coexpression of Galpha(i) or Galpha(i) S48C. Pertussis toxin treatment of the transfected cells enhanced the inhibition of the receptor-stimulated PLC by wild-type Galpha(i) subunits but did not influence the effects of the dominant negative mutant. The enhancement of the wild-type Galpha(i) inhibitory effect by pertussis toxin can be explained by stabilization of Galpha(i) binding to beta as a result of ADP-ribosylation, while Galpha(i) S48C mutant binds beta irreversibly even without pertussis toxin treatment. Therefore, a feasible mechanism to rationalize the attenuation of the Galpha and G-mediated activation of PLC by cotransfected Galpha(i) is the competition between Galpha(i) and Galpha or G for the beta complexes, which are necessary for the G protein coupling with receptors. These experiments provide new evidence for the role of beta in the integration of signals controlling phosphoinositide release through different Galpha families