Conserved, unstructured regions in Pseudomonas aeruginosa PilO are important for type IVa pilus function

Leighton, Tiffany L.; Mok, Mac C.Y.; Junop, M.S.; Howell, P. Lynne; Burrows, Lori L.

doi:10.1038/s41598-018-20925-w

Cited by 15 publications

(9 citation statements)

References 50 publications

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“…In T4P assembly systems, the CTD of the PulM orthologue PilO also forms homodimers but with β-sheets facing the opposite sides in the two protomers (Sampaleanu et al ., 2009, Leighton et al ., 2016, 2018).…”

Section: Resultsmentioning

confidence: 99%

Structure and dynamic association of an assembly platform subcomplex of the bacterial type II secretion system

Dazzoni

López-Castilla

et al. 2022

Preprint

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Type II secretion systems (T2SS) allow diderm bacteria to secrete hydrolytic enzymes, adhesins or toxins important for growth and virulence. In T2SS, secretion of folded proteins from the periplasm to the cell surface requires assembly of periplasmic filaments called pseudopili. Like the related type IV pili, pseudopili are polymerized in the inner membrane through addition of subunits at the filament base, mediated by the essential assembly platform (AP). To understand the structure and molecular role of the AP, we focused on its components PulL and PulM from the Klebsiella oxytoca T2SS. By combining biophysical methods, NMR and Xray crystallography we studied the structure and associations of their periplasmic domains. We describe the first structure of the heterodimer complex formed by the PulL and PulM ferredoxin-like domains and show how their structural complementarity and plasticity favor their association during the secretion process. Cysteine scanning and cross-linking of transmembrane segments provided additional constraints to build a structural model of the PulLPulM complex and assembly in the cellular context. Together with the relative abundance of PulL, PulM and their partners our findings suggest a model of the AP as a dynamic hub that orchestrates pseudopilus polymerization.

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Section: Resultsmentioning

confidence: 99%

Structure and dynamic association of an assembly platform subcomplex of the bacterial type II secretion system

Dazzoni

López-Castilla

et al. 2022

Preprint

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“…PilO and PilN are integral inner membrane proteins that play an important role in type IV pilus formation, which is essential for pathogenicity, DNA transformation, and motility [ 34 , 35 ]. The distribution of pilO varied among the four clonal complexes ( Table 1 and Figure 2 ).…”

Section: Discussionmentioning

confidence: 99%

Correlation of Moraxella catarrhalis macrolide susceptibility with the ability to adhere and invade human respiratory epithelial cells

Liu

Ding

Jia

et al. 2022

Emerging Microbes & Infections

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Recently, the prevalence of macrolide-resistant Moraxella catarrhalis has been reported, especially among Chinese children. The fitness cost of resistance is reported to render the resistant bacteria less virulent. To investigate the correlation between macrolide susceptibility of M. catarrhalis and pathogenicity, the whole genome of 70 M. catarrhalis isolates belonging to four clonal complexes with different macrolide susceptibilities was sequenced. The gene products were annotated with the Gene Ontology terms. Based on 46 extracted essential virulence genes, 19 representative isolates were selected to infect type II alveolar cells (A549 cells). The ability of these isolates to adhere and invade human epithelial cells and to produce cytokines was comparatively analysed. Furthermore, mice were infected with a pair of M. catarrhalis isolates with different pathogenic behaviours and macrolide susceptibilities to examine pulmonary clearance, histological findings, and the production of cytokines. The percentages of annotations for binding, metabolic process, cellular process, and cell were non-significantly different between the macrolide-resistant and macrolide-susceptible groups. The presence of uspA2 , uspA2H , pilO , lbpB , lex1 , modM , mboIA , and mboIB significantly differed among the four clonal complexes and macrolide susceptibility groups. Furthermore, compared with those in macrolide-susceptible isolates, the adhesion ability was stronger ( P = 0.0019) and the invasion ability was weaker ( P < 0.0001) in the macrolide-resistant isolates. Mouse experiments revealed that pulmonary macrophages elicit immune responses against M. catarrhalis infection by significantly upregulating the Csf2, Il4, Il13, Il1b, Il6, Tnf, and Il18. Therefore, M. catarrhalis populations exhibited diverse pathogenicity in vitro and in vivo .

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“…The twitching speed exhibited a negligible correlation with surface roughness (Figure S8). T4P have an outer diameter of approximately 5–8 nm and vary in length from 0.5 to 7 μm, much larger than the measured polymer RMS roughness . Thus, it appears unlikely that polymer topography affects bacterial motility.…”

Section: Resultsmentioning

confidence: 90%

“…T4P have an outer diameter of approximately 5–8 nm and vary in length from 0.5 to 7 μm, much larger than the measured polymer RMS roughness. 41 Thus, it appears unlikely that polymer topography affects bacterial motility. Physicochemical properties such as polymer wettability and stiffness were also considered.…”

Section: Resultsmentioning

confidence: 99%

Single-Cell Tracking on Polymer Microarrays Reveals the Impact of Surface Chemistry on Pseudomonas aeruginosa Twitching Speed and Biofilm Development

Carabelli

Isgró

Sanni

et al. 2020

ACS Appl. Bio Mater.

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Bacterial biofilms exhibit up to 1000 times greater resistance to antibiotic or host immune clearance than planktonic cells. Pseudomonas aeruginosa produces retractable type IV pili (T4P) that facilitate twitching motility on surfaces. The deployment of pili is one of the first responses of bacteria to surface interactions and because of their ability to contribute to cell surface adhesion and biofilm formation, this has relevance to medical device-associated infections. While polymer chemistry is known to influence biofilm development, its impact on twitching motility is not understood. Here, we combine a polymer microarray format with time-lapse automated microscopy to simultaneously assess P. aeruginosa twitching motility on 30 different methacrylate/acrylate polymers over 60 min post inoculation using a high-throughput system. During this critical initial period where the decision to form a biofilm is thought to occur, similar numbers of bacterial cells accumulate on each polymer. Twitching motility is observed on all polymers irrespective of their chemistry and physical surface properties, in contrast to the differential biofilm formation noted after 24 h of incubation. However, on the microarray polymers, P. aeruginosa cells twitch at significantly different speeds, ranging from 5 to ∼13 nm/s, associated with crawling or walking and are distinguishable from the different cell surface tilt angles observed. Chemometric analysis using partial least-squares (PLS) regression identifies correlations between surface chemistry, as measured by time-of-flight secondary ion mass spectrometry (ToF-SIMS), and both biofilm formation and single-cell twitching speed. The relationships between surface chemistry and these two responses are different for each process. There is no correlation between polymer surface stiffness and roughness as determined by atomic force measurement (AFM), or water contact angle (WCA), and twitching speed or biofilm formation. This reinforces the dominant and distinct contributions of material surface chemistry to twitching speed and biofilm formation.

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Conserved, unstructured regions in Pseudomonas aeruginosa PilO are important for type IVa pilus function

Cited by 15 publications

References 50 publications

Structure and dynamic association of an assembly platform subcomplex of the bacterial type II secretion system

Structure and dynamic association of an assembly platform subcomplex of the bacterial type II secretion system

Correlation of Moraxella catarrhalis macrolide susceptibility with the ability to adhere and invade human respiratory epithelial cells

Single-Cell Tracking on Polymer Microarrays Reveals the Impact of Surface Chemistry on Pseudomonas aeruginosa Twitching Speed and Biofilm Development

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