Biology subjects

Li, C.

Publications and source records attributed to Li, C..

At least 919 records · Page 51Linked to original sources

bioRxiv2020

Effects of Starter Feeds of Different Physical Forms on Rumen Fermentation and Microbial Composition for Pre-weaning and Post-weaning Lambs

This study aimed to evaluate the effects of starter feeds of different physical forms on rumen fermentation and microbial composition for lambs. Twenty-four eight-day-old male Hu lambs (5.04 {+/-} 0.75 kg body weight) were fed either milk replacer (MR) and pelleted starter feed (PS), or MR and textured starter feed (TS) in pre-weaning (day 8 to 35) and post-weaning (day 36 to 42) lambs. And the MR was fed by bottles to lambs at 2% of body weight at day 8 divided as three equal amounts at 08:00, 14:00 and 20:00 in pre-weaning. And the lambs were readily availed starter feeds and clean fresh water in the whole experiment. Six lambs for each treatment were euthanized at day 21 or 42 for sampling. The results showed the total volatile fatty acids, propionate and butyrate of rumen liquid in TS groups were all higher than them in PS groups respectively for pre-weaning and post-weaning lambs (P < 0.05), and the pH of rumen liquid in TS group was lower than it in PS group for post-weaning lambs (P < 0.05). Moreover, the pH of rumen and OTUs in TS group had trends to lower than them in PS group for pre-weaned lambs (P = 0.061, P = 0.066). TS established the predominant Phylum, Bacteroidetes, earlier than PS, and increased significantly the relative abundances of Sharpea compared to PS at level of genus (P < 0.05) for pre-weaning and post-weaning lambs. TS were more benefits to trigger rumen development for lambs. IMPORTANCEEarly use of starter feed could trigger rumen fermentation and establishment of dominant flora, which were in favour of growth and development of rumen for ruminants. The physical form of starter feed is one of the important factors to promote rumen fermentation and establishment of dominant flora for ruminants of transition. However, limited study on effects of physical forms of starter feeds, especially the texturized starters containing steam-flaked grains, to rumen fermentative pattern and microbial composition for pre-weaning and post-weaning lambs to date. It was necessary to investigate the effects of physical form of starter feed on rumen fermentation and microbial composition for lambs. The significance of our research showed TS were better benefits to promote the rumen fermentation and establishment of dominant flora for lambs, which will greatly enhance our understanding of physical forms of starter feeds, leading to broader studies on rumen development for lambs.

developmental biology↗

bioRxiv2020

A valid protective immune response elicited in rhesus macaques by an inactivated vaccine is capable of defending against SARS-CoV-2 infection

With the relatively serious global epidemic outbreak of SARS-CoV-2 infection, public concerns focus on not only clinical therapeutic measures and public quarantine for this disease but also the development of vaccines. The technical design of our SARS-CoV-2 inactivated vaccine provides a viral antigen that enables the exposure of more than one structural protein based upon the antibody composition of COVID-19 patients convalescent serum. This design led to valid immunity with increasing neutralizing antibody titers and a CTL response detected post-immunization of this vaccine by two injections in rhesus macaques. Further, this elicited immunoprotection in macaques enables not only to restrain completely viral replication in tissues of immunized animals, compared to the adjuvant control and those immunized by an RBD peptide vaccine, but also to significantly alleviate inflammatory lesion in lung tissues in histo-pathologic detection, compared to the adjuvant control with developed interstitial pneumonia. The data obtained from these macaques immunized with the inactivated vaccine or RBD peptide vaccine suggest that immunity with a clinically protective effect against SARS-CoV-2 infection should include not only specific neutralizing antibodies but also specific CTL responses against at least the S and N antigens.

immunology↗

bioRxiv2020

A genetic probe for visualizing glutamatergic synapses and vesicles by 3D electron microscopy

Communication between neurons relies on the release of diverse neurotransmitters, which represent a key-defining feature of a neurons chemical and functional identity. Neurotransmitters are packaged into vesicles by specific vesicular transporters. However, tools for labeling and imaging synapses and synaptic vesicles based on their neurochemical identity remain limited. We developed a genetically encoded probe to identify glutamatergic synaptic vesicles at the levels of both light and electron microscopy (EM) by fusing the mini singlet oxygen generator (miniSOG) probe to an intra-lumenal loop of the vesicular glutamate transporter-2. We then used a 3D imaging method, serial block face scanning EM, combined with a deep learning approach for automatic segmentation of labeled synaptic vesicles to assess the subcellular distribution of transporter-defined vesicles at nanometer scale. These tools represent a new resource for accessing the subcellular structure and molecular machinery of neurotransmission and for transmitter-defined tracing of neuronal connectivity.

neuroscience↗

bioRxiv2020

Conflict Processing in Schizophrenia: Dissociable Neural Mechanisms Revealed by the N2 and Frontal Midline Theta

Deficits in executive control have long been regarded as one of the hallmark cognitive characteristics in people with schizophrenia (SZ), and current neurocognitive models of SZ generally regard the dysfunctional anterior cingulate cortex (ACC) as the possible neural mechanism. This however, contrasts with recent studies showing that conflict processing, a key component of executive functions that relies on ACC, remains relatively intact in SZ. The current study aimed to investigate this issue through two well-known electrophysiological signatures of conflict processing that have been suggested to origin from ACC, i.e., the N2 component of event-related potentials (ERPs) and frontal midline theta (FM{theta}) oscillations. We recorded 64-channel scalp electroencephalography from 29 SZ (17 women; mean age: 30.4 years) and 31 healthy control subjects (HC; 17 women; mean age: 29.1 years) performing a modified flanker task. Behavioral data revealed no significant differences in flanker conflict effects (lower accuracy and longer reaction time in incongruent trials than in congruent trials) between HC and SZ. Trial-averaged ERP and spectral analysis suggested that both N2 and FM{theta} were significantly impaired in SZ relative to HC. Furthermore, by sorting incongruent trials according to their reaction times within individual subjects, we found that the trial-by-trial modulation of N2 (larger amplitude and longer latency in slower trials) which was observed and localized in ACC in HC was totally absent in SZ. By contrast, the trial-by-trial modulation of FM{theta} (larger power in slower trials) was observed and localized in ACC in both groups, despite a relatively smaller magnitude in SZ. Notably, such trial-by-trial FM{theta} modulation was only present in incongruent trials that demanded conflict processing. Taken together, our results not only support the idea that FM{theta}, not N2, serves as the neural substrate of conflict processing in SZ, but also provide novel insights into the functional roles of ACC during executive control, enriching the current neurocognitive models of SZ.

neuroscience↗

bioRxiv2020

Cerebrospinal fluid (CSF) boosts metabolism and virulence expression factors in Acinetobacter baumannii

In a recent report by the Centers for Disease Control and Prevention (CDC), multidrug resistant (MDR) Acinetobacter baumannii is a pathogen described as an "urgent threat". Infection with this bacterium manifests as different diseases such as community and nosocomial pneumonia, bloodstream infections, endocarditis, urinary tract, wound infections, burn infections, skin and soft tissue infections, and meningitis. In particular, nosocomial meningitis, a common complication of neurosurgery caused by extensively-drug resistant (XDR) A. baumannii, is extremely challenging to manage. Therefore, it is necessary to identify signals, such as exposure to cerebrospinal fluid (CSF), that trigger expression of virulence factors that are associated with the successful establishment and progress of this infection. While a hypervirulent A. baumannii strain did not show changes in its transcriptome when incubated in the presence of CSF, a low-virulence isolate showed significant differences in gene expression and phenotypic traits. Exposure to 4% CSF caused increased expression of virulence factors such as fimbriae, pilins, and iron chelators, and virulence as determined in various model systems. Furthermore, although CSFs presence did not enhance bacterial growth, it was associated with an increase of expression of genes encoding transcription, translation, and the ATP synthesis machinery. Experiments to identify the active CSF component pointed to human serum albumin (HSA). ImportanceAcinetobacter baumannii, notorious for its multidrug resistant phenotype, overcomes nutrient deprived and desiccated conditions through its metabolic flexibility, pathogenic and physiological adaptability. Although this pathogen is commonly associated with respiratory infections, there have been a considerable amount of cases of A. baumannii bacterial meningitis. These infections are usually post-neurological surgery complications associated with high mortality rates ranging from 40 to 70%. This work describes interactions that may occur during A. baumannii infection of human cerebrospinal fluid (CSF). A. baumanniis displays capabilities to persist and thrive in a nutrient-limited environment, which also triggers the expression of virulence factors. This work also further explores A. baumanniis utilization of an essential component within CSF to trigger enhanced expression of genes associated with its pathoadaptibility in this environment.

microbiology↗

bioRxiv2020

Transcriptome profiling reveals the mechanism of ripening and epidermal senescence in passionfruit (Passiflora edulia Sims)

Passion fruit (Passiflora edulia Sims), an important tropical and sub-tropical species, is classified as a respiration climacteric fruit, the quality deteriorates rapidly after harvest. To reveal the mechanisms involved in ripening and rapidly fruit senescence, the phytochemical characteristics and RNA sequencing were conducted in the purple passion fruits with different (1-MCP and PF) treatment. Comprehensive functional annotation and KEGG enrichment analysis showed that the starch and sucrose metabolism, plant hormone signal transduction, phenylpropanoid biosynthesis, flavonid biosynthesis, carotenoid biosynthesis were involved in fruit ripening. Applying with PF and 1-MCP significantly affected transcript levels of passion fruit after harvest storage. A large number of differently expressed unigenes (DEGs) were identified significantly enrichen in starch and sucrose metabolism, plant hormone signal transduction and phenylpropanoid biosynthesis at postharvest stage. The preservative film (PF) and 1-Methylcyclopropene (1-MCP) treatments increased superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) gene expression and enzyme activities, accelerated the lignin accumulation, decline {beta}-galactosidase ({beta}-Gal), polygalacturonase (PG) and cellulose activities and gene expression to delay cell wall degradation during fruit senescence. The RNA sequencing data of cell wall metabolism and hormone signal transduction pathway related unigenes were verified by RT-qPCR. The results indicated that the cell wall metabolism and hormone signal pathways were notably related to passion fruit ripening. PF and 1-MCP treatment might inhibited ethylene signaling and regulated cell wall metabolism pathways to inhibited cell wall degradation. Our results reveal ripening and senescence related networks during passion fruit ripening, which can provide a foundation for understanding the molecular mechanisms underlying PF and 1-MCP treatment on fruit ripening.

plant biology↗

bioRxiv2020

Enrofloxacin shifts intestinal microbiota and metabolic profiling and hinders recovery from Salmonella enterica subsp. enterica serovar Typhimurium infection in neonatal chickens

Enrofloxacin is an important antibiotic used for prevention and treatment of Salmonella infection in poultry in many countries. However, oral administration of enrofloxacin may lead to the alterations in the microbiota and metabolome in the chicks intestine, thereby reducing colonization resistance to the Salmonella infection. To study the effects of enrofloxacin on chicken cecal Salmonella, we used different concentrations of enrofloxacin to feed 1-day-old chickens, followed by oral challenge with Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium). We then explored the distribution patterns of S. Typhimurium in vivo in intestinal contents using quantitative polymerase chain reaction and microbial 16S amplicon sequencing on days 7, 14, and 21. Metabolome sequencing was used to explore the gut metabolome on day 14. Faecalibacterium and Anaerostipes, which are closely related to the chicken intestinal metabolome, were screened using a multi-omics technique. The abundance of S. Typhimurium was significantly higher in the enrofloxacin-treated group than in the untreated group, and S. Typhimurium persisted longer. Moreover, the cecal colony structures of the three groups exhibited different characteristics, with Lactobacillus reaching its highest abundance on day 21. Notably, S. Typhimurium infection is known to affect the fecal metabolome of chickens differently. Thus, our results suggested that enrofloxacin and Salmonella infections completely altered the intestinal metabolism of chickens. IMPORTANCEIn this study, we examined the effects of S. Typhimurium infection and enrofloxacin treatment on the microbial flora and metabolite synthesis in chicken guts in order to identify target metabolites that may cause S. Typhimurium colonization and severe inflammation and to evaluate the important flora that may be associated with these metabolites. Our findings may facilitate the use of antibiotics to prevent S. Typhimurium infection.

microbiology↗

bioRxiv2020

Multiscale Simulation Reveals Passive Proton Transport Through SERCA on the Microsecond Timescale

The sarcoplasmic reticulum Ca2+-ATPase (SERCA) transports two Ca2+ ions from the cytoplasm to the reticulum lumen at the expense of ATP hydrolysis. In addition to transporting Ca2+, SERCA facilitates bidirectional proton transport across the sarcoplasmic reticulum to maintain the charge balance of the transport sites and to balance the charge deficit generated by the exchange of Ca2+. Previous studies have shown the existence of a transient water-filled pore in SERCA that connects the Ca2+-binding sites with the lumen, but the capacity of this pathway to sustain passive proton transport has remained unknown. In this study, we used the multiscale reactive molecular dynamics (MS-RMD) method and free energy sampling to quantify the free energy profile and timescale of the proton transport across this pathway while also explicitly accounting for the dynamically coupled hydration changes of the pore. We find that proton transport from the central binding site to the lumen has a microsecond timescale, revealing a novel passive cytoplasm-to-lumen proton flow beside the well-known inverse proton countertransport occurring in active Ca2+ transport. We propose that this proton transport mechanism is operational and serves as a functional conduit for passive proton transport across the sarcoplasmic reticulum. SIGNIFICANCEMultiscale reactive molecular dynamics combined with free energy sampling was applied to study proton transport through a transient water pore connecting the Ca2+-binding site to the lumen in SERCA. This is the first computational study of this large biomolecular system that treats the hydrated excess proton and its transport through water structures and amino acids explicitly. When also correctly accounting for the hydration fluctuations of the pore, it is found that a transiently hydrated channel can transport protons on a microsecond timescale. These results quantitatively support the hypothesis of the proton intake into the sarcoplasm via SERCA, in addition to the well-known proton pumping by SERCA to the cytoplasm along with Ca2+ transport.

biophysics↗

bioRxiv2020

AMPlify: attentive deep learning model for discovery of novel antimicrobial peptides effective against WHO priority pathogens

Antibiotic resistance is a growing global health concern prompting researchers to seek alternatives to conventional antibiotics. Antimicrobial peptides (AMPs) are emerging therapeutic agents with promising utility in this domain and using in silico methods to discover novel AMPs is a strategy that is gaining interest. Such methods can filter through large volumes of candidate sequences and reduce lab screening costs. Here we introduce AMPlify, an attentive deep learning model for AMP prediction, and demonstrate its utility in prioritizing peptide sequences derived from the Rana [Lithobates] catesbeiana (bullfrog) genome. We tested the bioactivity of our predicted peptides against a panel of bacterial species, including representatives from the World Health Organizations "priority pathogens" list. Four of our novel AMPs were active against multiple species of bacteria, including a multi-drug resistant isolate of carbapenemase-producing Escherichia coli, demonstrating the utility of tools like AMPlify in our fight against antibiotic resistance.

bioinformatics↗

bioRxiv2020

Direct RNA sequencing reveals structural differences between transcript isoforms

The ability to correctly assign structure information to an individual transcript in a continuous and phased manner is critical to understanding RNA function. RNA structure play important roles in every step of an RNAs lifecycle, however current short-read high throughput RNA structure mapping strategies are long, complex and cannot assign unique structures to individual gene-linked isoforms in shared sequences. To address these limitations, we present an approach that combines structure probing with SHAPE-like compound NAI-N3, nanopore direct RNA sequencing, and one-class support vector machines to detect secondary structures on near full-length RNAs (PORE-cupine). PORE-cupine provides rapid, direct, accurate and robust structure information along known RNAs and recapitulates global structural features in human embryonic stem cells. The majority of gene-linked isoforms showed structural differences in shared sequences both local and distal to the alternative splice site, highlighting the importance of long-read sequencing for phasing of structures. Structural differences between gene-linked isoforms are associated with differential translation efficiencies globally, highlighting the role of structure as a pervasive mechanism for regulating isoform-specific gene expression inside cells.

biochemistry↗

bioRxiv2020

Identification and verification of 3 key genes associated with survival and prognosis of patients with colon adenocarcinoma via integrated bioinformatics analysis

BackgroundColorectal cancer (CRC) is the third most lethal malignancy in the world, wherein colon adenocarcinoma (COAD) is the most prevalent type of CRC. Exploring biomarkers is important for the diagnosis, treatment, and prevention of COAD. MethodsWe used GEO2R and Venn online software for differential gene screening analysis. Hub genes were screened via STRING and Cytoscape, following Gene Ontology and KEGG enrichment analysis. Finally, survival analysis and expression validation were performed via UALCAN online software, real-time PCR and immunohistochemistry. ResultsIn this study, we screened 323 common differentially expressed genes from four GSE datasets. Furthermore, four hub genes were selected for survival correlation analysis and expression level verification, three of which were shown to be statistically significant. ConclusionOur study suggests that SERPINE1, SPP1 and TIMP1 may be biomarkers closely related to the prognosis of CRC patients.

bioinformatics↗

bioRxiv2020

A method for continuously monitoring the quality of Masson pine seedlings

Root growth potential (RGP) is a popular physiological indicator used to evaluate seedling vigor. However, the time scale used in the RGP test is the order of days, which leads to poor performance of the RGP method. We propose an optical interference method, called statistical interferometry, to measure minute root elongation at a sub-nanometer scale, which can decrease the time used in measuring RGP. The time scale of this method is also 104 times less than that of the RGP method. Because we can measure the length of root elongation continuously, we can compute the root elongation rate (RER), which is the variety of the length of root elongation per second. Continuous monitoring can help determine the quality of Masson pine seedling as soon as possible. To show the effectiveness of our proposed method, we designed an experiment, in which we applied different water stresses to our collected Masson pine seedlings and acquired two groups of pines, representing two different qualities: one stressed by water and one not. After measuring the RER of the groups in our experiments, we found that RER is interrelated with the quality of seedlings. Author summaryLi Wang have worked in Nanjing Forest University. His interesting includes machine learning, computer vision and plant phenotype.

plant biology↗

bioRxiv2020

Repurposing screen identifies Amlodipine as an inducer of PD-L1 degradation and antitumor immunity

Cancer cell expression of PD-L1 leads to T cells exhaustion by transducing co-inhibitory signal, and further understanding the regulation of PD-L1 in cancer cells may provide additional therapeutic strategies. Here by drug repurposing screen we identified amlodipine as a potent inhibitor of PD-L1 expression in cancer cells. Further survey of calcium-associated pathways revealed calpains-dependent stabilization of the PD-L1 protein. Intracellular calcium delivered an operational signal to calpain-dependent Beclin-1 cleavage, blocking autophagic degradation of PD-L1 accumulated on recycling endosome (RE). Blocking calcium flux by amlodipine depleted PD-L1 expression and increased CD8+ T cell infiltration in tumor tissues but not in myocardium, causing dose-dependent tumor suppression in vivo. Rescuing PD-L1 expression eliminated the effects of amlodipine, suggesting the PD-L1 dependent effect of amlodipine. These results reveal a calcium-dependent mechanism controlling PD-L1 degradation, and highlight calcium flux blockade as a potential strategy for combinatorial immunotherapy.

cancer biology↗

bioRxiv2020

Slc26a9P2ACre, a new CRE driver to regulate gene expression in the otic placode lineage and other FGFR2b-dependent epithelia

Pan-otic CRE drivers enable gene regulation throughout the otic placode lineage, comprising the inner ear epithelium and neurons. However, intersection of extra-otic gene-of-interest expression with the CRE lineage can compromise viability and impede auditory analyses. Furthermore, extant pan-otic CREs recombine in auditory and vestibular brain nuclei, making it difficult to ascribe resulting phenotypes solely to the inner ear. We previously identified Slc26a9 as an otic placode-specific target of FGFR2b ligands, FGF3 and FGF10. We show here that Slc26a9 is otic-specific through E10.5, but not required for hearing. We targeted P2ACre to the Slc26a9 stop codon, generating Slc26a9P2ACre mice, and observed CRE activity throughout the otic epithelium and neurons, with little activity evident in the brain. Notably, recombination was detected in many FGFR2b ligand-dependent epithelia. We generated Fgf10 and Fgf8 conditional mutants, and activated an FGFR2b ligand trap from E17.5-P3. In contrast to analogous mice generated with other pan-otic CREs, these were viable. Auditory thresholds were elevated in mutants, and correlated with cochlear epithelial cell losses. Thus, Slc26a9P2ACre provides a useful complement to existing pan-otic CRE drivers, particularly for postnatal analyses. Summary statementWe describe a new pan-otic CRE driver, Slc26a9P2ACre, with little activity in the brain or middle ear, and demonstrate its utility by manipulating FGF signaling and assessing hearing loss.

developmental biology↗

bioRxiv2020

The H-NS regulator plays a role in the stress induced by carbapenemase expression in Acinetobacter baumannii

Disruption of the histone-like nucleoid structuring protein (H-NS) was shown to affect the ability for Gram-negative bacteria to regulate genes associated with virulence, persistence, stress response, quorum sensing, biosynthesis pathways and cell adhesion. Here, we used the expression of metallo-{beta}-lactamases (MBLs) known to elicit envelope stress by the accumulation of toxic species in the periplasm to interrogate the role of H-NS in Acinetobacter baumannii, together with other stressors. Using a multidrug-resistant A. baumannii, we observed that H-NS plays a role in alleviating the stress triggered by MBL toxic precursors and counteract the effect of DNA-damaging agents, supporting its role in stress response. ImportanceCarbapenem-resistant A. baumannii (CRAB) is recognized as one of the most threatening gram-negative bacilli. H-NS is known to play a role in controlling the transcription of a variety of different genes, including those associated with stress response, persistence and virulence. In the present work, we uncovered a link between the role of H-NS in the A. baumannii stress response and its relationship with the envelope stress response and resistance to DNA-damaging agents. Overall, we posit a new role of H-NS, showing that H-NS serves to endure envelope stress that could also be a mechanism that alleviates the stress induced by MBL expression in A. baumannii. This could be an evolutionary advantage to further resist the action of carbapenems.

microbiology↗

bioRxiv2020

Molecular Mechanism for Rotational Switching of the Bacterial Flagellar Motor

The bacterial flagellar motor is a remarkable nanomachine that can rapidly rotate in both counter-clockwise (CCW) and clockwise (CW) senses. The transitions between CCW and CW rotation are critical for chemotaxis, and they are controlled by a signaling protein (CheY-P) that interacts with a switch complex at the cytoplasmic side of the flagellar motor. However, the exact molecular mechanism by which CheY-P controls the motor rotational switch remains enigmatic. Here, we use the Lyme disease spirochete, Borrelia burgdorferi, as the model system to dissect the mechanism underlying flagellar rotational switching. We first determined high resolution in situ motor structures in the cheX and cheY3 mutants in which motors are genetically locked in CCW or CW rotation. The structures showed that the CheY3 protein of B. burgdorferi interacts directly with the FliM protein of the switch complex in a phosphorylation-dependent manner. The binding of CheY3-P to FliM induces a major remodeling of the switch protein FliG2 that alters its interaction with the torque generator. Because the remodeling of FliG2 is directly correlated with the rotational direction, our data lead to a model for flagellar function in which the torque generator rotates in response to an inward flow of H+ driven by the proton motive force. Rapid conformational changes of FliG2 allow the switch complex to interact with opposite sides of the rotating torque generator, thereby facilitating rotational switching between CW and CCW.

microbiology↗

bioRxiv2020

CATA: a comprehensive chromatin accessibility database for cancer

Chromatin accessibility is a crucial epigenetic concept that plays a biological role in oncology. As humans become more involved in cancer research, a comprehensive database is required to identify and annotate tumor chromatin accessible regions (CARs). Here, CATA was developed to provide cancer-related CAR annotation. Currently, CATA possesses 2,991,163 CARs, relevant clinical data, and transcription factor binding predictions for cancer CARs from 410 tumor samples of 24 cancer types. Furthermore, CARs were annotated by SNPs, risk SNPs, eQTLs, linkage disequilibrium SNPs, transcription factors, CNV, SNV, enhancer, and 450K methylation sites in our database. By combining all these resources, we believe that CATA will provide better service for researchers on oncology. Our database is accessible at http://bio.licpathway.net/cata/Competing Interest StatementThe authors have declared no competing interest.View Full Text

bioinformatics↗

bioRxiv2020

Visualizing the dynamics of exported bacterial proteins with the chemogenetic fluorescent reporter FAST

Bacterial proteins exported to the cell surface play key cellular functions. However, despite the interest to study the localization of surface proteins such as adhesins, transporters or hydrolases, monitoring their dynamics in live imaging remains challenging, due to the limited availability of fluorescent probes remaining functional after secretion. In this work, we used the Escherichia coli intimin and the Listeria monocytogenes InlB invasin as surface exposed scaffolds fused with the recently developed chemogenetic fluorescent reporter protein FAST. Using both membrane permeant (HBR-3,5DM) and non-permeant (HBRAA-3E) fluorogens that fluoresce upon binding to FAST, we demonstrated that fully functional FAST can be exposed at the cell surface and specifically tagged on the external side of the bacterial envelop in both diderm and monoderm bacteria. Our work opens new avenues to study of the organization and dynamics of the bacterial cell surface proteins.

microbiology↗