The development of new approaches to control cardiac arrhythmias requires a deep understanding of spiral wave dynamics. Optogenetics offers new possibilities for this. Preliminary experiments show that sub-threshold illumination affects electrical wave propagation in the mouse heart. https://www.selleckchem.com/products/gw3965.html However, a systematic exploration of these effects is technically challenging. Here, we use state-of-the-art computer models to study the dynamic control of spiral waves in a two-dimensional model of the adult mouse ventricle, using stationary and non-stationary patterns of sub-threshold illumination. Our results indicate a light-intensity-dependent increase in cellular resting membrane potentials, which together with diffusive cell-cell coupling leads to the development of spatial voltage gradients over differently illuminated areas. A spiral wave drifts along the positive gradient. These gradients can be strategically applied to ensure drift-induced termination of a spiral wave, both in optogenetics and in conventional methods of electrical defibrillation.Protein modification by SUMO helps orchestrate the elaborate events of meiosis to faithfully produce haploid gametes. To date, only a handful of meiotic SUMO targets have been identified. Here, we delineate a multidimensional SUMO-modified meiotic proteome in budding yeast, identifying 2747 conjugation sites in 775 targets, and defining their relative levels and dynamics. Modified sites cluster in disordered regions and only a minority match consensus motifs. Target identities and modification dynamics imply that SUMOylation regulates all levels of chromosome organization and each step of meiotic prophase I. Execution-point analysis confirms these inferences, revealing functions for SUMO in S-phase, the initiation of recombination, chromosome synapsis and crossing over. K15-linked SUMO chains become prominent as chromosomes synapse and recombine, consistent with roles in these processes. SUMO also modifies ubiquitin, forming hybrid oligomers with potential to modulate ubiquitin signaling. We conclude that SUMO plays diverse and unanticipated roles in regulating meiotic chromosome metabolism.The genera Proteus and Cosenzaea are closely related members of the family Morganellaceae. The genus Cosenzaea consists of the species Cosenzaea myxofaciens originally separated from the genus Proteus by rpoB gene analysis. Due to the high similarity of the 16S rRNA genes between species of both genera, the taxonomic status is here re-evaluated by a genome-based approach. Based on a core genome phylogeny and genome relatedness indices, it is shown that the taxonomy and nomenclature given for the basonym Proteus myxofaciens is more appropriate. Therefore, we propose to use this name in preference. Furthermore, the species status of Proteus terrae and Proteus cibarius was reassessed. Both species are related at subspecies level by digital DNA-DNA hybridization (dDDH) analysis. Additionally, average amino acid identity (AAI) and average nucleotide identity (ANI) do not support a separate species status, and therefore it is proposed to classify P. cibarius as a subspecies of P. terrae. Consequently, both species are being renamed Proteus terrae subsp. cibarius subsp. nov. and Proteus terrae subsp. terrae subsp. nov., respectively. The genome relatedness indices revealed a close relationship of the Proteus genomospecies 5 with P. terrae subsp. terrae. Thus, it has been assigned to the same subspecies.Biofilm formation in the human intestinal pathogen Vibrio cholerae is in part regulated by norspermidine, spermidine and spermine. V. cholerae senses these polyamines through a signalling pathway consisting of the periplasmic protein, NspS, and the integral membrane c-di-GMP phosphodiesterase MbaA. NspS and MbaA belong to a proposed class of novel signalling systems composed of periplasmic ligand-binding proteins and membrane-bound c-di-GMP phosphodiesterases containing both GGDEF and EAL domains. In this signal transduction pathway, NspS is hypothesized to interact with MbaA in the periplasm to regulate its phosphodiesterase activity. Polyamine binding to NspS likely alters this interaction, leading to the activation or inhibition of biofilm formation depending on the polyamine. The purpose of this study was to determine the amino acids important for NspS function. We performed random mutagenesis of the nspS gene, identified mutant clones deficient in biofilm formation, determined their responsiveness to norspermidine and mapped the location of these residues onto NspS homology models. Single mutants clustered on two lobes of the NspS model, but the majority were found on a single lobe that appeared to be more mobile upon norspermidine binding. We also identified residues in the putative ligand-binding site that may be important for norspermidine binding and interactions with MbaA. Ultimately, our results provide new insights into this novel signalling pathway in V. cholerae and highlight differences between periplasmic binding proteins involved in transport versus signal transduction.Four novel bacterial strains (ST-M6T, L-033, L-031T and Z-333) were isolated from the intestinal contents of plateau pikas (Ochotona curzoniae) collected on the Qinghai-Tibet Plateau, PR China. Cells were aerobic, non-motile, Gram-stain-positive, catalase-positive, oxidase-negative, capsuled and short-rod-shaped. Phylogenetic analyses based on the 16S rRNA gene sequences and 387 core genes indicated that the four isolates belong in the genus Microbacterium and clearly separate from recognized species. The two type strains (ST-M6T and L-031T) shared low 16S rRNA similarity, average nucleotide identity values and digital DNA-DNA hybridization relatedness with their phylogenetic neighbours (Microbacterium ginsengisoli DSM 18659T, Microbacterium hatanonis DSM 19179T, Microbacterium rhizomatis JCM 30598T, Microbacterium radiodurans CCTCC M208212T, Microbacterium oleivorans DSM 16091T and Microbacterium arborescens DSM 20754T). The genomic DNA G+C contents of strains ST-M6T and L-031T were 70.4 and 70.7 mol%, respectively. The major cellular fatty acids of strain ST-M6T were anteiso-C15  0, anteiso-C17  0 and iso-C16  0, in contrast to anteiso-C17  0, anteiso-C15  0 and anteiso-C17  1 ω9c of strain L-031T. Both type strains (ST-M6T and L-031T) were glycolate test positive and shared the following common features MK-11 and MK-12 as major menaquinones; rhamnose, ribose, mannose and galactose as major cell-wall sugars; diphosphatidylglycerol, phosphatidylglycerol and two glycolipids as polar lipids; and ornithine, alanine, glycine and glutamic acid as cell-wall amino acids. Comparing the phenotypic, phylogenetic and chemotaxonomic features of the four strains and their related taxa, strains ST-M6T and L-031T represent two novel species of the genus Microbacterium, for which the names Microbacterium caowuchunii sp. nov. (type strain ST-M6T=CGMCC 1.16364T=DSM 104058T) and Microbacterium lushaniae sp. nov. (type strain L-031T =CGMCC 1.16363T=DSM 106170T) are proposed.