Biology subjects

Park, H.

Publications and source records attributed to Park, H..

At least 199 records · Page 11Linked to original sources

bioRxiv2019

Rapid antimicrobial susceptibility test using spatiotemporal analysis of laser speckle dynamics of bacterial colonies

Antimicrobial susceptibility testing (AST) is crucial for providing appropriate choices and doses of antibiotics to patients. However, standard ASTs require a time-consuming incubation of about 16-20 h for visual accumulation of bacteria, limiting the use of AST for an early prescription. In this study, we propose a rapid AST based on laser speckle formation (LSF) that enables rapid detection of bacterial growth, with the same sample preparation protocol as in solid-based ASTs. The proposed method exploits the phenomenon that well-grown bacterial colonies serve as optical diffusers, which convert a plane-wave laser beam into speckles. The generation of speckle patterns indicates bacterial growth at given antibiotic concentrations. Speckle formation is evaluated by calculating the spatial autocorrelation of speckle images, and bacterial growth is determined by tracking the autocorrelation value over time. We demonstrated the performance of the proposed method for several combinations of bacterial species and antibiotics to achieve the AST in 2-4.5 hours. Furthermore, we also demonstrated the sensitivity of the technique for low bacterial density. The proposed method can be a powerful tool for rapid, simple, and low-cost AST. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=160 SRC="FIGDIR/small/853168v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@8ee314org.highwire.dtl.DTLVardef@de47c5org.highwire.dtl.DTLVardef@13a0103org.highwire.dtl.DTLVardef@118ad36_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2019

Improved protein structure prediction using predicted inter-residue orientations

The prediction of inter-residue contacts and distances from co-evolutionary data using deep learning has considerably advanced protein structure prediction. Here we build on these advances by developing a deep residual network for predicting inter-residue orientations in addition to distances, and a Rosetta constrained energy minimization protocol for rapidly and accurately generating structure models guided by these restraints. In benchmark tests on CASP13 and CAMEO derived sets, the method outperforms all previously described structure prediction methods. Although trained entirely on native proteins, the network consistently assigns higher probability to de novo designed proteins, identifying the key fold determining residues and providing an independent quantitative measure of the "ideality" of a protein structure. The method promises to be useful for a broad range of protein structure prediction and design problems.

bioinformatics↗

bioRxiv2019

Scaffold-free human mesenchymal stem cell construct geometry regulates long bone regeneration

Scaffold-based bone tissue engineering approaches frequently induce repair processes dissimilar to normal developmental programs. In contrast, biomimetic strategies aim to recapitulate aspects of development through cellular self-organization, morphogenetic pathway activation, and mechanical cues. This may improve regenerative outcome in large long bone defects that cannot heal on their own; however, no study to date has investigated the role of scaffold-free construct geometry, in this case tubes mimicking long bone diaphyses, on bone regeneration. We hypothesized that microparticle-mediated in situ presentation of transforming growth factor-{beta}1 (TGF-{beta}1) and bone morphogenetic protein-2 (BMP-2) to engineered human mesenchymal stem cell (hMSC) tubes induces the endochondral cascade, and that TGF-{beta}1 + BMP-2-presenting hMSC tubes facilitate enhanced endochondral healing of critical-sized femoral segmental defects under delayed in vivo mechanical loading conditions compared to loosely-packed hMSC sheets. Here, localized morphogen presentation imparted early chondrogenic lineage priming, and stimulated robust endochondral differentiation of hMSC tubes in vitro. In an ectopic environment, hMSC tubes formed a cartilage template that was actively remodeled into trabecular bone through endochondral ossification without lengthy predifferentiation. Similarly, hMSC tubes stimulated in vivo cartilage and bone formation and more robust healing in femoral defects compared to hMSC sheets. New bone was formed through endochondral ossification in both groups; however, only hMSC tubes induced regenerate tissue partially resembling normal growth plate architecture. Together, this study demonstrates the interaction between mesenchymal cell condensation geometry, bioavailability of multiple morphogens, and defined in vivo mechanical environment to recapitulate developmental programs for biomimetic bone tissue engineering.\n\nSignificance StatementEngineered bone constructs must be capable of withstanding and adapting to harsh conditions in a defect site upon implantation, and can be designed to facilitate repair processes that resemble normal developmental programs. Self-assembled tubular human mesenchymal stem cell constructs were engineered to resemble the geometry of long bone diaphyses. By mimicking the cellular, biochemical, and mechanical environment of the endochondral ossification process during embryonic development, successful healing of large femoral segmental defects upon implantation was achieved and the extent was construct geometry dependent. Importantly, results were obtained without a supporting scaffold or lengthy predifferentiation of the tubular constructs. This indicates that adult stem/progenitor cells retain features of embryonic mesenchyme, and supports the concept of developmental engineering for bone regeneration approaches.

bioengineering↗

bioRxiv2019

PICH promotes SUMOylated TopoisomeraseIIα dissociation from mitotic centromeres for proper chromosome segregation

Polo-like kinase interacting checkpoint helicase (PICH) is a SNF2 family DNA translocase and is a Small Ubiquitin-like modifier (SUMO) binding protein. Despite that both translocase activity and SUMO-binding activity are required for proper chromosome segregation, how these two activities function to mediate chromosome segregation remains unknown. Here, we show that PICH specifically promotes dissociation of SUMOylated TopoisomeraseII (TopoII) from mitotic chromosomes. When TopoII is stalled by treatment of cells with a potent TopoII inhibitor, ICRF-193, TopoII becomes SUMOylated, and this promotes its interaction with PICH. Conditional depletion of PICH using the Auxin Inducible Degron (AID) system resulted in retention of SUMOylated TopoII on chromosomes, indicating that PICH removes stalled SUMOylated TopoII from chromosomes. In vitro assays showed that PICH specifically regulates SUMOylated TopoII activity using its SUMO-binding and translocase activities. Taken together, we propose a novel mechanism for how PICH acts on stalled SUMOylated TopoII for proper chromosome segregation.\n\nSummary StatementPolo-like kinase interacting checkpoint helicase (PICH) interacts with SUMOylated proteins to mediate proper chromosome segregation during mitosis. The results demonstrate that PICH promotes dissociation of SUMOylated TopoisomeraseII from chromosomes and that function leads to proper chromosome segregation.

cell biology↗

bioRxiv2019

Albumin inhibits the activation of hepatic stellate cells by suppressing TGF-β/Smad3 signaling via IL-1β

Activated hepatic stellate cells (HSCs) play a key role in liver fibrosis and inactivating HSCs has been considered a promising therapeutic approach. We previously showed that albumin and its derivative, retinol binding protein (RBP)-albumin domain III fusion protein (named R-III), inhibit HSC activation. Here, we investigate the mode of action of albumin and R-III. NF-{kappa}B in activated HSCs was evenly distributed in the cytoplasm, but albumin expression and R-III treatment (albumin/R-III) induced NF-{kappa}B nuclear translocation via retinoic acid (RA) sequestration, resulting in increased expression of interleukin-1{beta} (IL-1{beta}). In an IL-1{beta} dependent manner, albumin/R-III inhibited Smad3 nuclear translocation via TAK1-, JNK-mediated Smad3 linker phosphorylation and decreased expression of Smad3 target genes, such as -smooth muscle actin and collagen type I. Mutation of the Smad3 linker phosphorylation sites abolished R-III effects on Smad3. In conclusion, our data suggest that the anti-fibrotic effects of albumin/R-III are due to RA sequestration which downregulates RAR-mediated signaling and also TGF-{beta}/Smad3 signaling. This mechanistic elucidation of albumin function in HSCs provides clues to understanding the frequent albumin mutations found in hepatocellular carcinoma.

molecular biology↗

bioRxiv2019

Liver-Chip: Reproducing Human and Cross-Species Toxicities

Nonclinical rodent and non-rodent toxicity models used to support clinical trials of candidate drugs may produce discordant results or fail to predict complications in humans contributing to drug failures in the clinic. Here we applied microengineered Organ-on-Chip (Organ-Chip) technology to design rat, dog, and human Liver-Chips containing species-specific primary hepatocytes interfaced with liver sinusoidal endothelial cells, with or without Kupffer cells and hepatic stellate cells, cultured under physiological fluid flow. The Liver-Chips detected diverse phenotypes of liver toxicity including hepatocellular injury, steatosis, cholestasis, and fibrosis as well as species-specific toxicities when treated with tool compounds. Multi-species Liver-Chips may provide a useful platform for prediction of liver toxicity and inform human relevance of liver toxicities detected in animal studies to better determine safety and human risk.\n\nOne Sentence SummaryMicroengineered Organ-Chip technology has been used to design rat, dog and human Liver-Chips that recapitulate species-specific liver toxicities.

pharmacology and toxicology↗

bioRxiv2019

Efficient consideration of coordinated water molecules improves computational protein-protein and protein-ligand docking

Highly-coordinated water molecules are frequently an integral part of protein-protein and protein-ligand interfaces. We introduce an updated energy model that efficiently captures the energetic effects of these highly-coordinated water molecules on the surfaces of proteins. A two-stage protocol is developed in which polar groups arranged in geometries suitable for water placement are first identified, then a modified Monte Carlo simulation allows highly coordinated waters to be placed on the surface of a protein while simultaneously sampling amino acid side chain orientations. This \"semi-explicit\" water model is implemented in Rosetta and is suitable for both structure prediction and protein design. We show that our new approach and energy - model yield significant improvements in native structure recovery of protein-protein and protein-ligand docking.

biochemistry↗

bioRxiv2019

HDX-MS reveals structural determinants for RORγ hyperactivation by synthetic agonists

Members of the nuclear receptor (NR) superfamily regulate both physiological and pathophysiological processes ranging from development and metabolism1 to inflammation2 and cancer3. As ligand-gated transcription factors, synthetic small molecules targeting NRs are often deployed as therapeutics to correct aberrant NR signaling or as chemical probes to explore the role of the receptor in physiology4. However, nearly half of NRs do not have specific cognate ligands or its unclear if they possess ligand dependent activities and these receptors are called orphans. Here we demonstrate that ligand-dependent action of the orphan nuclear receptor ROR{gamma} can be defined by selectively disrupting putative endogenous--but not synthetic--ligand binding. Furthermore, the characterization of a library of ROR{gamma} modulators reveals that structural dynamics of the receptor assessed by HDX-MS correlate with activity in biochemical and cell-based assays. These findings are corroborated with X-ray co-crystallography and site-directed mutagenesis to collectively reveal the structural determinants of ROR{gamma} ligand-dependent activation, critical for designing full agonists for application in cancer immunotherapy. Combined these observations support a model of receptor activation to more accurately describe ROR{gamma} pharmacology. Likewise, this bump-and-hole inspired approach could be extended to other orphan NRs to explore the ligand-dependent activities that are important for defining pharmacology.

biophysics↗

bioRxiv2019

Shared neural underpinnings of multisensory integration and trial-by-trial perceptual recalibration

Multisensory stimuli create behavioral flexibility, e.g. by allowing us to derive a weighted combination of the information received by different senses. They also allow perception to adapt to discrepancies in the sensory world, e.g. by biasing the judgement of unisensory cues based on preceding multisensory evidence. While both facets of multisensory perception are central for behavior, it remains unknown whether they arise from a common neural substrate. In fact, very little is known about the neural mechanisms underlying multisensory perceptual recalibration. To reveal these, we measured whole-brain activity using MEG while human participants performed an audio-visual ventriloquist paradigm designed to reveal multisensory integration within a trial, and the (trial-by-trial) recalibration of subsequent unisensory judgements. Using single trial classification and behavioral modelling, we localized the encoding of sensory information within and between trials, and determined the behavioral relevance of candidate neural representations. While we found neural signatures of perceptual integration within temporal and parietal regions, of these, only medial superior parietal activity retained multisensory information between trials and combined this with current evidence to mediate perceptual recalibration. These results suggest a common neural substrate of sensory integration and trial-by-trial perceptual recalibration, and expose the medial superior parietal cortex as a flexible hub that links present and previous evidence within and between senses to guide behavior.

neuroscience↗

bioRxiv2019

Inverted translational control of eukaryotic gene expression by ribosome collisions

The canonical model of eukaryotic translation posits that efficient translation initiation increases protein expression and mRNA stability. Contrary to this dogma, we show that increasing initiation rate can decrease both protein expression and stability of certain mRNAs in the budding yeast, S. cerevisiae. These mRNAs contain a stretch of poly-basic residues that cause ribosome stalling. Using computational modeling, we predict that the observed decrease in gene expression at high initiation rates occurs when ribosome collisions at stalls stimulate abortive termination of the leading ribosome and cause endonucleolytic mRNA cleavage. We test our prediction by identifying critical roles for the collision-associated quality control factors, Asc1 and Hel2 (RACK1 and ZNF598 in humans, respectively). Remarkably, hundreds of S. cerevisiae mRNAs that contain ribosome-stall sequences also exhibit lower translation efficiency. We propose that these mRNAs have undergone evolutionary selection for inefficient initiation to escape collision-stimulated reduction in gene expression.

molecular biology↗

bioRxiv2019

Combinatorial morphogenetic and mechanical cues to mimic bone development for defect repair

Endochondral ossification during long bone development and natural fracture healing initiates by mesenchymal cell condensation and is directed by local morphogen signals and mechanical cues. Here, we aimed to mimic these developmental conditions for regeneration of large bone defects. We hypothesized that engineered human mesenchymal stem cell (hMSC) condensations with in situ presentation of transforming growth factor-{beta}1 (TGF-{beta}1) and/or bone morphogenetic protein-2 (BMP-2) from encapsulated microparticles would promote endochondral regeneration of critical-sized rat femoral bone defects in a manner dependent on the in vivo mechanical environment. Mesenchymal condensations induced bone formation dependent on morphogen presentation, with dual BMP-2 + TGF-{beta}1 fully restoring mechanical bone function by week 12. In vivo ambulatory mechanical loading, initiated at week 4 by delayed unlocking of compliant fixation plates, significantly enhanced the bone formation rate in the four weeks after load initiation in the dual morphogen group. In vitro, local presentation of either BMP-2 alone or BMP-2 + TGF-{beta}1 initiated endochondral lineage commitment of mesenchymal condensations, inducing both chondrogenic and osteogenic gene expression through SMAD3 and SMAD5 signaling. In vivo, however, endochondral cartilage formation was evident only in the BMP-2 + TGF-{beta}1 group and was enhanced by mechanical loading. The degree of bone formation was comparable to BMP-2 soaked on collagen but without the ectopic bone formation that limits the clinical efficacy of BMP-2/collagen. In contrast, mechanical loading had no effect on autograft-mediated repair. Together, this study demonstrates a biomimetic template for recapitulating developmental morphogenic and mechanical cues in vivo for tissue engineering. One Sentence SummaryMimicking aspects of the cellular, biochemical, and mechanical environment during early limb development, chondrogenically-primed human mesenchymal stem cell condensations promoted functional healing of critical-sized femoral defects via endochondral ossification, and healing rate and extent was a function of the in vivo mechanical environment.

bioengineering↗

bioRxiv2019

Chromokinesins NOD and KID Use Distinct ATPase Mechanisms and Microtubule Interactions to Perform a Similar Function

Chromokinesins NOD and KID have similar DNA binding domains and functions during cell division, while their motor domain sequences show significant variations. It has been unclear whether these motors have similar structure, chemistry, and microtubule interactions necessary to follow a similar mechanism of force mediation. We used biochemical rate measurements, cosedimentation, and structural analysis to investigate the ATPase mechanisms of the NOD and KID core domains. These experiments and analysis revealed that NOD and KID have different ATPase mechanisms, microtubule interactions, and catalytic domain structures. The ATPase cycles of NOD and KID have different rate limiting steps. The ATPase rate of NOD was robustly stimulated by microtubules albeit its microtubule affinity was weakened in all nucleotide bound states. KID bound microtubules tightly in all nucleotide states and remained associated with the microtubule for more than 100 cycles of ATP hydrolysis before dissociating. The structure of KID was most similar to conventional kinesin (KIF5). Key differences in the microtubule binding region and allosteric communication pathway between KID and NOD are consistent with our biochemical data. Our results support the model that NOD and KID utilize distinct mechanistic pathways to achieve the same function during cell division.

biochemistry↗

bioRxiv2018

Causal inference in the multisensory brain

When combining information across different senses humans need to flexibly select cues of a common origin whilst avoiding distraction from irrelevant inputs. The brain could solve this challenge using a hierarchical principle, by deriving rapidly a fused sensory estimate for computational expediency and, later and if required, filtering out irrelevant signals based on the inferred sensory cause(s). Analysing time- and source-resolved human magnetoencephalographic data we unveil a systematic spatio-temporal cascade of the relevant computations, starting with early segregated unisensory representations, continuing with sensory fusion in parietal-temporal regions and culminating as causal inference in the frontal lobe. Our results reconcile previous computational accounts of multisensory perception by showing that prefrontal cortex guides flexible integrative behaviour based on candidate representations established in sensory and association cortices, thereby framing multisensory integration in the generalised context of adaptive behaviour.

neuroscience↗

bioRxiv2018

Cartilaginous and osteochondral tissue formation by human mesenchymal stem cells on three-dimensionally woven scaffolds

The development of mechanically functional cartilage and bone tissue constructs of clinically relevant size, as well as their integration with native tissues, remain important challenges for regenerative medicine. The objective of this study was to assess adult human mesenchymal stem cells (MSC) in large, three dimensionally woven poly({varepsilon}-caprolactone) (PCL) scaffolds in proximity to viable bone, both in a nude rat subcutaneous pouch model and under simulated conditions in vitro. In Study I, various scaffold permutations: PCL alone, PCL-bone, \"point-of- care\" seeded MSC-PCL-bone, and chondrogenically pre-cultured Ch-MSC-PCL-bone constructs were implanted in a dorsal, ectopic pouch in a nude rat. After eight weeks, only cells in the Ch- MSC-PCL constructs exhibited both chondrogenic and osteogenic gene expression profiles. Notably, while both tissue profiles were present, constructs that had been chondrogenically pre- cultured prior to implantation showed a loss of glycosaminoglycan (GAG) as well as the presence of mineralization along with the formation of trabecula-like structures. In Study II of the study, the GAG loss and mineralization observed in Study I in vivo were recapitulated in vitro by the presence of either nearby bone or osteogenic culture medium additives but were prevented by a continued presence of chondrogenic medium additives. These data suggest conditions under which adult human stem cells in combination with polymer scaffolds synthesize functional and phenotypically distinct tissues based on the environmental conditions, and highlight the potential influence that paracrine factors from adjacent bone may have on MSC fate, once implanted in vivo for chondral or osteochondral repair.

bioengineering↗

bioRxiv2018

An efficient genome editing strategy to generate putative null mutants in Caenorhabditis elegans using CRISPR/Cas9

Null mutants are essential for analyzing gene function. Here, we describe a simple and efficient method to generate Caenorhabditis elegans null mutants using CRISPR/Cas9 and short single stranded DNA oligo repair templates to insert a universal 43-nucleotide-long stop knock-in (STOP-IN) cassette into the early exons of target genes. This cassette has stop codons in all three reading frames and leads to frameshifts, which will generate putative null mutations regardless of the reading frame of the insertion position in exons. The STOP-IN cassette also contains an exogenous Cas9 target site that allows further genome editing and provides a unique sequence that simplifies the identification of successful insertion events via PCR. As a proof of concept, we inserted the STOP-IN cassette right at a Cas9 target site in aex-2 to generate new putative null alleles by injecting preassembled Cas9 ribonucleoprotein and a short synthetic single stranded DNA repair template containing the STOP-IN cassette and two 35-nucleotide-long homology arms identical to the sequences flanking the Cas9 cut site. We showed that these new aex-2 alleles phenocopied an existing loss-of-function allele of aex-2. We further showed that the new aex-2 null alleles could be reverted back to the wild-type sequence by targeting exogenous Cas9 cut site included in the STOP-IN cassette and providing a single stranded wild-type DNA repair oligo. We applied our STOP-IN method to generate new putative null mutants for additional 20 genes, including three pharyngeal muscle-specific genes (clik-1, clik-2, and clik-3), and reported a high insertion rate (46%) based on the animals we screened. We showed that null mutations of clik-2 cause recessive lethality with a severe pumping defect and clik-3 null mutants have a mild pumping defect, while clik-1 is dispensable for pumping. We expect that the knock-in method using the STOP-IN cassette will facilitate the generation of new null mutants to understand gene function in C. elegans and other genetic model organisms.\n\nSummaryWe report a simple and efficient CRISPR/Cas9 genome editing strategy to generate putative null C. elegans mutants by inserting a small universal stop knock-in (STOP-IN) cassette with stop codons in three frames and frameshifts. The strategy is cloning-free, with the mixture consisting of preassembled Cas9 ribonucleoprotein and single stranded repair DNA oligos directly injected into gonads of adult C. elegans. The universal STOP-IN cassette also contains a unique sequence that simplifies detection of successful knock-in events via PCR and an exogenous Cas9 target sequence that allows further genome editing.

genetics↗

bioRxiv2018

Human primary motor cortex represents evidence for a perceptual decision before motor response

In perceptual decision making the brain extracts and accumulates decision evidence from a stimulus over time and eventually makes a decision based on the accumulated evidence. Several characteristics of this process have been observed in human electrophysiological experiments, especially an average build-up of motor-related signals supposedly reflecting accumulated evidence, when averaged across trials. A more direct approach to investigate the representation of decision evidence in brain signals is to correlate the trial-to-trial fluctuations of a model-based prediction of evidence with the measured signals. We here report results for an experiment in which we applied this approach to human magnetoencephalographic recordings. These results consolidate a range of previous findings and suggest that decision evidence is processed in three consecutive phases in the human brain: In an early phase around 120 ms after the evidence became visible on the screen, in a transition phase around 180 ms and a plateau phase roughly from 300 to 500 ms. We located sources of evidence representations in these phases in early visual (early), parietal (transition) and motor (plateau) regions of the brain while signals in posterior cingulate cortex represented decision evidence in all three phases. These findings imply that parietal cortex is only transiently involved in the processing of decision evidence, that motor areas represent accumulated evidence throughout decision making and that posterior cingulate cortex may have a central role in processing and maintaining decision evidence.

neuroscience↗

bioRxiv2018

Heterogeneous timing of asexual cycles in Plasmodium falciparum quantified by extended time-lapse microscopy

Malarial fever arises from the synchronous bursting of human red blood cells by the Plasmodium parasite. The released parasites re-infect neighboring red blood cells and undergo another asexual cycle of differentiation and proliferation for 48 hours, before again bursting synchronously. The synchrony of bursting is lost during in vitro culturing of the parasite outside the human body, presumably because the asexual cycle is no longer entrained by host-specific circadian cues. Therefore, most in vitro malaria studies have relied on the artificial synchronization of the parasite population. However, much remains unknown about the degree of timing heterogeneity of asexual cycles and how artificial synchronization may affect this timing. Here, we combined time-lapse fluorescence microscopy and long-term culturing to follow single cells and directly measure the heterogeneous timing of in vitro asexual cycles. We first demonstrate that unsynchronized laboratory cultures are not fully asynchronous and the parasites exhibit a bimodal distribution in their first burst times. We then show that synchronized and unsynchronized cultures had similar asexual cycle periods, which indicates that artificial synchronization does not fundamentally perturb asexual cycle dynamics. Last, we demonstrate that sibling parasites descended from the same schizont exhibited significant variation in asexual cycle period, although smaller than the variation between non-siblings. The additional variance between non-siblings likely arises from the variable environments and/or developmental programs experienced in different host cells.

microbiology↗

bioRxiv2018

Cell adhesion promoted by a unique Shigella IpaA vinculin- and talin-binding site

During Shigella cell invasion, the IpaA effector targets the focal adhesion protein vinculin through three vinculin-binding sites (VBSs). Here, we report that IpaA VBS3 also binds to talin. The 2.5 [A] resolution crystal structure indicates that IpaA VBS3 forms a tightly folded -helical bundle with talin H1-H4, contrasting with bundle unraveling upon vinculin interaction. High-affinity binding of Ipa VBS3 to talin H1-H4 requires a core of hydrophobic residues conserved in vinculin binding and a pair of electrostatic interactions accounting for talin binding specificity. IpaA VBS3 does not bind to talin H1-H5 suggesting the targeting of partially activated stretched talin but not inactive talin. Consistently, IpaA VBS3 labeled filopodial and nascent adhesions and regulated their formation through talin binding. In addition, talin-binding by IpaA VBS3 was required for bacterial capture by filopodia during Shigella invasion and for the stabilization of focal adhesions in infected cells. These findings point to the functional diversity of VBSs and a critical role for talin-binding by Shigella IpaA VBS3 and possibly talin VBSs in the regulation of adhesion structures.

microbiology↗