Alexandra Possling's research while affiliated with Humboldt-Universität zu Berlin and other places

... The involvement of the Lon protease in resistance to acidic stress is rather poorly investigated across different bacterial species. In E. coli, Lon is responsible for the degradation of the activator of acidic resistance, GadE, playing a role in the termination of the stress response [38]. Additionally, S. enterica serovar Typhimurium requires this protease to successfully cope with low pH [16]; however, the precise mechanism was not provided. ...

... Besides having c-di-GMP synthesizing activity, DgcM can also activate MlrA by directly interacting with its C-terminal ligand domain (Lindenberg et al., 2013). This interaction is inhibited by PdeR, but with the increasing concentration of c-di-GMP with DgcE and DgcQ, PdeR will no longer be available to be a barrier between the interaction of DgcM with MlrA and thus release and activates MlrA (Klauck, Serra, Possling, & Hengge, 2018). This activated form of MlrA binds to the upstream region near to another activator OmpA site on the csgD promoter and thus initiates the transcription of csgD . ...

... Conventional detection methods for microarrays often use fluorescent dyes, which were detected by irradiation from a laser scanner. Detection methods are discussed intensively elsewhere (Espina et al. 2004;Feilner et al. 2004), while in this study, only new approaches should be pointed out to reach much higher sensitivities. With a special method called MIST (multiple spotting technique) (Angenendt et al. 2003a, b), multiple spotting steps are performed successively to one position. ...

... In the recent few years, it has become significantly established that modified nucleotides, such as c-di-GMP (second messenger represents a signaling system that regulates many bacterial biofilm formation), plays a crucial role as signaling molecule for biofilm formation. Furthermore, c-di-GMP stimulates the production of various adhesion factors via the different mechanisms, which may ignite the biofilm formation process into the bacterial cell, i.e., allosteric activation (protein stabilization or regulation of gene expression at the transcriptional and translational levels) [53][54][55][56][57][58]. Due to the, different penetration rate of AgNPs, the inhibition concentration differs between Gram-positive and Gram-negative strain. ...

... In vitro assays for evaluation of protein-protein interactions have been in use for many years (Beveridge 2003;Michaud 2003;Sutandy 2013;Paul 2016;Sjoberg 2016). These have been employed for a variety of purposes such as protein-protein interaction screening, antibody-epitope mapping, and antibody specificity assessment. ...

... Therefore, protein microarrays were also employed as a tool for phosphoproteomic analysis, as this allows detection of phosphorylation targets as well as molecular interactions using thousands of immobilized probable protein targets [32][33][34][35]. This technique was first employed for A. thaliana proteins [36]. Before designing the high-throughput microarrays with A. thaliana kinases [37], low throughput microarrays were designed to understand the number of microarrays analyzed for one phosphorylation on one microarray [38,39] followed by medium throughput with barley kinases [40]. ...

... The semisolid medium was prepared according to the literature method (Pesavento et al. 2008). The bacterial strains were transferred to fresh LB broth and cultured at 30℃ and 37 ℃ for 200 rpm to OD 600 = 1.0, respectively. ...

... Using this technique to investigate A. thaliana transcription factor (TF) interactions, a deep-coverage A. thaliana TF interaction network was created (AtTFIN-1), greatly expanding the number of known plant TF interactions ( Trigg et al., 2017). Other systematic approaches include classic in vitro protein arrays (Feilner et al., 2005;Popescu et al., 2007Popescu et al., , 2009 • Interactome studies mentioning hubs are marked with a gray background. ...

... In the context of protein detection, protein array technologies provide a valuable platform for functional proteomic analysis (Ray et al. 2010). A protein microarray provides a multi-functional platform enabling comprehensive and high throughput studies, which can be widely used in biomarker validation studies (Hudson et al. 2007), study of protein-protein interactions (Schweitzer et al. 2003), protein-DNA interactions (Kersten et al. 2004), and detection of various antigens and antibodies (Chamritski et al. 2007). Among affinity-based biosensing technologies, there are two major detection strategies, label-based and labelfree. ...

... Its genome contains genes for 12 DGCs (with this activity residing in GGDEF domains), 13 PDEs (with EAL domains providing PDE activity) as well as four "degenerate" GGDEF/EAL domain proteins [6,7], the latter with non-enzymatic functions relying on direct macromolecular interactions [8][9][10]. Nearly all of these GGDEF/EAL domain proteins are expressed and most of the DGCs are active when E. coli cells enter into stationary phase [11,12]. Moreover, several c-di-GMP-controlled targets are known for E. coli, with the underlying effector mechanisms having been analyzed at the molecular level. ...