Modified reaction centers from Rhodobacter sphaeroides R26

Incubation of photosynthetic reaction centers from Rhodobacter sphaeroides R26 with exogenous 132-OH-bacteriochlorophyll ap or aGG according to Scheer et al. (1987) results in the exchange of endogenous bacteriochlorophyll ap. The exchange amounts to less-than-or-equals, slant 50% according to HPLC analysis, corresponding to a complete replacement of the ‘monomeric’ bacteriochlorophylls, bm and bl, by exogenous pigment. The absorption spectra show small, but distinct changes in the Qx-region of the bacteriochlorophylls, and bleaching of the modified reaction centers is retained. The corresponding binding sites must be accessible from the exterior, and allow for the introduction of a polar residue at C-132. This is supported by the observation of side reactions of the endogenous ‘monomeric’ bacteriochlorophylls within the reaction center pigments, e.g. epimerization and hydroxylation at C-132

AC behaviour of full size, fusion dedicated cable-in-conduit conductors in SULTAN III under applied pulsed field

The coupling current-losses of a full size, fusion dedicated Nb3Sn cable-in-conduit superconductor are measured as a function of the transverse load in the SULTAN III test facility. Applying a broad range of transport current (up to 56 kA) and background field (up to 12.1 T), the change of the transverse resistance is observed through the shift of the 0-crossing in the pick-up coil voltage. Despite the difficulty to extract useful information from the signal, the role of the strand Cr plating as resistive barrier is experimentally assessed under operating conditions. The friction factor of the conductor is also evaluated front pressure drop measurements

The human Dcn1-like protein DCNL3 promotes Cul3 neddylation at membranes

Cullin (Cul)-based E3 ubiquitin ligases are activated through the attachment of Nedd8 to the Cul protein. In yeast, Dcn1 (defective in Cul neddylation 1 protein) functions as a scaffold-like Nedd8 E3-ligase by interacting with its Cul substrates and the Nedd8 E2 Ubc12. Human cells express 5 Dcn1-like (DCNL) proteins each containing a C-terminal potentiating neddylation domain but distinct amino-terminal extensions. Although the UBA-containing DCNL1 and DCNL2 are likely functional homologues of yeast Dcn1, DCNL3 also interacts with human Culs and is able to complement the neddylation defect of yeast dcn1Δ cells. DCNL3 down-regulation by RNAi decreases Cul neddylation, and overexpression of a Cul3 mutant deficient in DCNL3 binding interferes with Cul3 function in vivo. Interestingly, DCNL3 accumulates at the plasma membrane through a conserved, lipid-modified motif at the N terminus. Membrane-bound DCNL3 is able to recruit Cul3 to membranes and is functionally important for Cul3 neddylation in vivo. We conclude that DCNL proteins function as nonredundant Cul Nedd8-E3 ligases. Moreover, the diversification of the N termini in mammalian Dcn1 homologues may contribute to substrate specificity by regulating their subcellular localization

Fly Cell Atlas: A single-nucleus transcriptomic atlas of the adult fruit fly

For more than 100 years, the fruit fly Drosophila melanogaster has been one of the most studied model organisms. Here, we present a single-cell atlas of the adult fly, Tabula Drosophilae , that includes 580,000 nuclei from 15 individually dissected sexed tissues as well as the entire head and body, annotated to >250 distinct cell types. We provide an in-depth analysis of cell type–related gene signatures and transcription factor markers, as well as sexual dimorphism, across the whole animal. Analysis of common cell types between tissues, such as blood and muscle cells, reveals rare cell types and tissue-specific subtypes. This atlas provides a valuable resource for the Drosophila community and serves as a reference to study genetic perturbations and disease models at single-cell resolution