Structure, function and regulation of Pseudomonas aeruginosa porins

Abstract

Pseudomonas aeruginosa is a Gram-negative bacterium belonging to the γ-proteobacteria. Like other members of the Pseudomonas genus, it is known for its metabolic versatility and its ability to colonize a wide range of ecological niches, such as rhizosphere, water environments and animal hosts, including humans where it can cause severe infections. Another particularity of P. aeruginosa is its high intrinsic resistance to antiseptics and antibiotics, which is partly due to its low outer membrane permeability. In contrast to Enterobacteria, pseudomonads do not possess general diffusion porins in their outer membrane, but rather express specific channel proteins for the uptake of different nutrients. The major outer membrane 'porin', OprF, has been extensively investigated, and displays structural, adhesion and signaling functions while its role in the diffusion of nutrients is still under discussion. Other porins include OprB and OprB2 for the diffusion of glucose, the two small outer membrane proteins OprG and OprH, and the two porins involved in phosphate/pyrophosphate uptake, OprP and OprO. The remaining nineteen porins belong to the so-called OprD (Occ) family, which is further split into two subfamilies termed OccD (8 members) and OccK (11 members). In the past years, a large amount of information concerning the structure, function and regulation of these porins has been published, justifying why an updated review is timely.

Engineering the Osmotic State of Pseudomonas putida KT2440 for Efficient Cell Disruption and Downstream Processing of Poly(3-Hydroxyalkanoates)

“…Figures 2C,D show that the KT2440 strains carrying the porin proteins boosted the hydrophobicity of the membrane by more than threefold in comparison to the parental and the mutant KT mscL strain. The OprF protein contributed the most to this process, as this is the major waterfilling porin in Pseudomonas (Chevalier et al, 2017). Consistent with the enhanced hydrophobicity of the cell's surface of the engineered KT2440 strains, changes in the uptake of N-phenyl-1-naphtylamina (NPN) were found, a suitable compound to assess the permeability barrier of the membrane (Helander and Mattila-Sandholm, 2000).…”

“…This pleiotropic trans-outer-membrane porin is to a large extent responsible for cell wall permeability and integrity and further contributes to the maintenance of the cell shape. Besides ion incorporation (weakly biased to cations), it is also responsible for the passage of low molecular mass sugars, toluene, and nitrate/nitrite (Chevalier et al, 2017).…”

Ibuprofen-mediated potential inhibition of biofilm development and quorum sensing inPseudomonas aeruginosa

“…We used four different assays to assess the levels and activity of (1) pyocyanin, (2) elastase, (3) protease, and (4) rhamnolipids. Specific details for each assay are outlined below.…”

Host Peptidic Hormones Affecting Bacterial Biofilm Formation and Virulence

“…For instance, it was shown that interferon-γ led to the induction of the Pseudomonas aeruginosa lectin PA-I via activation of the quorum-sensing network that is required for the production of virulence factors [29]. Noticeably, this effect was shown to be triggered by direct binding of interferon-γ on OprF [29], which is a multifunctional outer membrane porin [30] that is required for P. aeruginosa virulence regulation [31] and involved in regulation of biofilm formation [32]. It has also been observed that dynorphin A, an endogenous opioid, modifies P. aeruginosa physiology [33].…”