Study of the plant COPII vesicle coat subunits by functional complementation of yeast Saccharomyces cerevisiae mutants

The formation and budding of endoplasmic reticulum ER-derived vesicles depends on the COPII coat protein complex that was first identified in yeast Saccharomyces cerevisiae. The ER-associated Sec12 and the Sar1 GTPase initiate the COPII coat formation by recruiting the Sec23-Sec24 heterodimer following the subsequent recruitment of the Sec13-Sec31 heterotetramer. In yeast, there is usually one gene encoding each COPII protein and these proteins are essential for yeast viability, whereas the plant genome encodes multiple isoforms of all COPII subunits. Here, we used a systematic yeast complementation assay to assess the functionality of Arabidopsis thaliana COPII proteins. In this study, the different plant COPII subunits were expressed in their corresponding temperature-sensitive yeast mutant strain to complement their thermosensitivity and secretion phenotypes. Secretion was assessed using two different yeast cargos: the soluble alpha-factor pheromone and the membranous v-SNARE (vesicle-soluble NSF (N-ethylmaleimide-sensitive factor) attachment protein receptor) Snc1 involved in the fusion of the secretory vesicles with the plasma membrane. This complementation study allowed the identification of functional A. thaliana COPII proteins for the Sec12, Sar1, Sec24 and Sec13 subunits that could represent an active COPII complex in plant cells. Moreover, we found that AtSec12 and AtSec23 were co-immunoprecipitated with AtSar1 in total cell extract of 15 day-old seedlings of A. thaliana. This demonstrates that AtSar1, AtSec12 and AtSec23 can form a protein complex that might represent an active COPII complex in plant cells

Update of the BIPM comparison BIPM.RI(II)-K1.Ho-166m activity measurements to include the IRA and the NPL and a re-evaluation of the degrees of equivalence for the APMP.RI(II)-K2.Ho-166m comparison

The IRA and the NPL have submitted ampoules of 166Hom to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures, thus becoming the third and fourth participants since 1989. The five samples of known activity of 166Hom now recorded in the SIR have activities between about 70 kBq and 500 kBq. The new results have enabled a re-evaluation of the key comparison reference value, and the degrees of equivalence between each equivalent activity measured in the SIR and the key comparison reference value (KCRV) have been calculated. The results are given in the form of a matrix for these four NMIs together with the recalculated degrees of equivalence of an APMP regional comparison held in 2000, comparison identifier APMP.RI(II)-K2.Ho-166m for six other NMIs. A graphical presentation is also given

Bias in the measurement of radon gas using ionization chambers: Application to SIR

Proceedings of the 21st International Conference on Radionuclide Metrology and its Applications (ICRM), 15-19 May 2017, Buenos Aires, Argentina. Organizer: Argentinian Comis Nacl Energia AtomicaInternational audienceTwo main non-destructive techniques can be used to measure standard Rn-222 gas ampoules: well-type ionization chambers and gamma-ray spectrometry, the former being used in the Systeme International de Reference (SIR) for international comparison purposes. The reliability of these techniques requires that the variability of the flame-sealed gas glass ampoules used have a negligible influence on the detector response. This variability is studied in this work by considering three parameters: the volume of the ampoule, the position of the sealing point and the thickness of the glass. Results showed that variability of the gas ampoules induced measurement bias larger than the uncertainty of the standard sources

Update of the BIPM comparison BIPM.RI(II)-K1.Cs-134 of activity measurements of the radionuclide 134Cs to include the 2008 results of the BEV (Austria), the 2009 result of the IRA (Switzerland) and the 2010 results of the NMISA (South Africa)

Purine nucleotide pyrophosphotransferase was purified to apparent homogeneity from a culture filtrate of Streptomyces morookaensis. It is a monomeric protein with a molecular weight of 24 000-25 000, and its isoelectric point is 6.9. The enzyme synthesizes purine nucleoside 5'-phosphate (mono, di, or tri) 3'-diphosphates such as pppApp, ppApp, pApp, pppGpp, ppGpp and pppIpp by transferring a pyrophosphoryl group from the 5'-position of ATP, dATP and ppApp to the 3'-position of purine nucleotides. The purified enzyme catalysed the formation of 435 mumol of pppApp and 620 mumol of pppGpp from ATP and GTP per min mg protein under the standard conditions. The enzyme requires absolutely a divalent cation for activity, and optimum pH for the enzyme activity lay above 10 for Mg2+, for Co2+ and Zn2+ from 9 to 9.5, and for Fe2+ from 7.5 to 8. The following Michaelis constants were determined: AMP, 2.78 mM; ADP, 3.23 mM; GMP, 0.89 mM; GDP, 0.46 mM and GTP, 1.54 mM, in the case of ATP donor. The enzyme is inhibited by guanine, guanosine, dGDP, dGTP, N-bromosuccinimide, iodacetate, sodium borate and mercuric acetate

Update of the BIPM comparison BIPM.RI(II)-K1.Cd-109 of activity measurements of the radionuclide 109^{109}Cd to include the 2012 result of the LNE-LNHB (France)

International audienceSince 1978, 10 laboratories have submitted 23 samples of $^{109}$Cd to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Cd-109. In 2012, the LNE-LNHB (France) participated in the comparison to update its degree of equivalence. A graphical presentation is also given

Der Patientenbegleitbogen Ein Instrument fuer die Kommunikation zwischen ambulanten Pflegediensten und Krankenhaeusern

SIGLEAvailable from TIB Hannover: RR9321(2000,1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Der Patientenbegleitbogen Ein Instrument fuer die Kommunikation zwischen ambulanten Pflegediensten und Krankenhaeusern

SIGLEAvailable from TIB Hannover: RR9321(2000,1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Final report of the new BIPM comparison BIPM.RI(II)-K1.Ra-223 of activity measurements of the radionuclide 223^{223} Ra including the 2014 result of the NPL (United Kingdom), the 2014 result of the PTB (Germany) and the 2018 result of the LNE-LNHB (France)

International audienceSince 2014, 3 laboratories have submitted 3 samples of 223 Ra to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ra-223. The NPL (United Kingdom), the PTB (Germany) and the LNE-LNHB (France) participated in the comparison and the key comparison reference value (KCRV) has been calculated for the first time. The degrees of equivalence between each equivalent activity measured in the SIR and the KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report . Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/ . The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA)