We analyse the evolutionary trajectory of a subset of highly conserved cyanobacterial proteins (core) along the plastid lineage, those which were not lost after the endosymbiosis. We concatenate the sequences of 33 cyanobacterial
core proteins that share a congruent evolutionary history, with their eukaryotic counterparts to reconstruct their phylogeny using sophisticated evolutionary models. We perform an independent reconstruction using concatenated 16S and 23S rRNA GS-1101 purchase sequences. These complementary approaches converge to a plastid origin occurring during the divergence of one of the major cyanobacterial lineages that include N-2-fixing filamentous cyanobacteria and species able to differentiate heterocysts.”
“A set of 49 protein nanopore-lipid bilayer systems was explored by means of coarse-grained molecular-dynamics simulations to study the interactions
between nanopores and the lipid bilayers in which they are embedded. The seven nanopore species investigated represent the two main structural classes of membrane proteins (alpha-helical and beta-barrel), and the seven different bilayer systems range in thickness from similar to 28 to similar to 43 angstrom. The study focuses on the local effects of hydrophobic mismatch between the nanopore and the lipid bilayer. The effects of nanopore insertion on lipid bilayer thickness, the dependence between hydrophobic thickness selleck and the observed nanopore tilt angle, and the local distribution of lipid types around a nanopore in mixed-lipid bilayers are all analyzed. Different BAY 63-2521 datasheet behavior for nanopores of similar hydrophobic length but different geometry is observed. The local lipid bilayer perturbation caused by the inserted nanopores suggests possible mechanisms for both lipid bilayer-induced protein sorting and protein-induced lipid sorting. A correlation
between smaller lipid bilayer thickness (larger hydrophobic mismatch) and larger nanopore tilt angle is observed and, in the case of larger hydrophobic mismatches, the simulated tilt angle distribution seems to broaden. Furthermore, both nanopore size and key residue types (e.g., tryptophan) seem to influence the level of protein tilt, emphasizing the reciprocal nature of nanopore-lipid bilayer interactions.”
“Antibodies have important roles in controlling cellular immunity through interaction with activating or inhibitory Fc gamma receptors (Fc gamma Rs). Fc gamma R engagement can facilitate receptor cross-linking on target cells, or induce retrograde Fc gamma R signals to stimulate or suppress antibody-dependent, cell-mediated depletion of antigen-bearing target cells. Recent studies uncover unexpectedly important roles for Fc gamma Rs in the anticancer action of antibodies designed to trigger tumor cell apoptosis or enhance antitumor immunity. Here, we outline a conceptual framework for understanding these findings and discuss their mechanistic and translational implications.