Alteration in the electrophoretic mobility of OmpC due to variations in the ammonium persulfate concentration in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis

Lobos, S R; Mora, Gabriela

doi:10.1002/elps.1150120615

Cited by 23 publications

(22 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To measure the relative abundance of OmpD in the serovar Typhimurium outer membrane, we prepared outer membrane fractions from cells grown at 37°C in Luria-Bertani (LB) medium as described by Schnaitman (24) and modified by Lobos and Mora (11), resolved the proteins in these fractions by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis in 12.5% slab gels, and revealed these proteins by staining with Coomassie blue. Figure 1 shows that when wild-type strain LT2 is grown aerobically in LB medium at 37°C, it produces four abundant porins, OmpC, OmpF, OmpD, and OmpA, among which OmpD is the most abundant.…”

mentioning

confidence: 99%

Global Regulation of the Salmonella enterica Serovar Typhimurium Major Porin, OmpD

et al. 2003

Self Cite

View full text Add to dashboard Cite

The OmpD porin is the most abundant outer membrane protein in Salmonella enterica serovar Typhimurium and represents about 1% of total cell protein. Unlike the case with the less abundant OmpC and OmpF porins, the stoichiometry of OmpD in the outer membrane does not change in response to changes in osmolarity. The abundance of OmpD increases in response to anaerobiosis and decreases in response to low pH, conditions encountered by serovar Typhimurium during the infection of its murine host. By constructing an operon fusion of the lacZY genes with the ompD promoter, we show that the abundance of OmpD in the outer membrane is regulated primarily at the level of transcription and is subject to catabolite repression. In response to anaerobiosis, the abundance of OmpD in the outer membrane also appears to be controlled posttranscriptionally by a function dependent on Fnr.

show abstract

mentioning

confidence: 99%

Global Regulation of the Salmonella enterica Serovar Typhimurium Major Porin, OmpD

et al. 2003

Self Cite

View full text Add to dashboard Cite

show abstract

“…Previously, we have shown that the protein with an apparent molecular mass of 36 kDa corresponds to the porin OmpC (12,44). Bands corresponding to the other induced proteins were isolated, and the N-terminal sequences of the proteins present in these bands were determined by sequential Edman degradation and are the sequences of serovar Typhi FliC (flagellin) and the MalL, PhoE, and Tsx porins ( Table 2).…”

Section: Resultsmentioning

confidence: 99%

“…Outer membrane fractions were prepared as described by Lobos and Mora (44) based on a modification of the method of Schnaitman (62), and proteins in these fractions were separated in 12.5% polyacrylamide gels. Bacteria were grown to the mid-exponential phase (optical density at 600 nm [OD 600 ], 0.2), chilled on ice, pelleted by centrifugation at 3,000 ϫ g for 15 min at 4°C, resuspended in lysis buffer (10 mM Tris-HCl, pH 8, 10 mM MgCl 2 ), and sonicated, and the preparations were supplemented with 2 mM phenylmethylsulfonyl fluoride.…”

mentioning

confidence: 99%

TheSalmonella entericaSerovar TyphitsxGene, Encoding a Nucleoside-Specific Porin, Is Essential for Prototrophic Growth in the Absence of Nucleosides

et al. 2005

Self Cite

View full text Add to dashboard Cite

The Salmonella enterica serovar Typhi tsx gene encodes a porin that facilitates the import of nucleosides. When serovar Typhi is grown under anaerobic conditions, Tsx is among the outer membrane proteins whose expression increases dramatically. This increase in expression is due, at least in part, to increased transcription and is dependent on Fnr but not on ArcA. A mutant derivative of serovar Typhi strain STH2370 with a deletion of the tsx gene is an auxotroph that requires either adenosine or thymidine for growth on minimal medium. In contrast, an otherwise isogenic nupG nupC double mutant, defective in the inner membrane nucleoside permeases, is a prototroph. Because anaerobic growth enhances the virulence of serovar Typhi in vitro, we assessed the role that the tsx gene plays in pathogenicity and found that the serovar Typhi STH2370 ⌬tsx mutant is defective in survival within human macrophage-like U937 cells. To understand why the ⌬tsx mutant is an auxotroph, we selected for insertions of minitransposon T-POP in the ⌬tsx genetic background that restored prototrophy. One T-POP insertion that suppressed the ⌬tsx mutation in the presence of the inducer tetracycline was located upstream of the pyrD gene. The results of reverse transcription-PCR analysis showed that addition of the inducer decreased the rate of pyrD transcription. These results suggest that the Tsx porin and the balance of products of the tsx and pyrD genes play critical roles in membrane assembly and integrity and thus in the virulence of serovar Typhi.

show abstract

“…Subcellular fractionation was performed by a modification of a method previously described (Lobos & Mora, 1991). Briefly, bacteria were cultured in LB pH 7.0 400 mM NaCl to exponential phase without aeration.…”

Section: Methodsmentioning

confidence: 99%

SPI-9 of Salmonella enterica serovar Typhi is constituted by an operon positively regulated by RpoS and contributes to adherence to epithelial cells in culture

et al. 2016

Self Cite

View full text Add to dashboard Cite

The genomic island 9 (SPI-9) from Salmonella enterica serovar Typhi (S. Typhi) carries three ORFs (STY2876, STY2877, STY2878) presenting 98 % identity with a type 1 secretory apparatus (T1SS), and a single ORF (STY2875) similar to a large RTX-like protein exhibiting repeated Ig domains. BapA, the Salmonella enterica serovar Enteritidis orthologous to S. Typhi STY2875, has been associated with biofilm formation, and is described as a virulence factor in mice. Preliminary in silico analyses revealed that S. Typhi STY2875 ORF has a 600 bp deletion compared with S. Enteritidis bapA, suggesting that S. Typhi STY2875 might be non-functional. At present, SPI-9 has not been studied in S. Typhi. We found that the genes constituting SPI-9 are arranged in an operon whose promoter was up-regulated in high osmolarity and low pH in a RpoS-dependent manner. All the proteins encoded by S. Typhi SPI-9 were located at the membrane fraction, consistent with their putative role as T1SS. Furthermore, SPI-9 contributed to adherence of S. Typhi to epithelial cells when bacteria were grown under high osmolarity or low pH. Under the test conditions, S. Typhi SPI-9 did not participate in biofilm formation. SPI-9 is functional in S. Typhi and encodes an adhesin induced under conditions normally found in the intestine, such as high osmolarity. Hence, this is an example of a locus that might be designated a pseudogene by computational approaches but not by direct biological assays.

show abstract

Alteration in the electrophoretic mobility of OmpC due to variations in the ammonium persulfate concentration in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis

Cited by 23 publications

References 13 publications

Global Regulation of the Salmonella enterica Serovar Typhimurium Major Porin, OmpD

Global Regulation of the Salmonella enterica Serovar Typhimurium Major Porin, OmpD

TheSalmonella entericaSerovar TyphitsxGene, Encoding a Nucleoside-Specific Porin, Is Essential for Prototrophic Growth in the Absence of Nucleosides

SPI-9 of Salmonella enterica serovar Typhi is constituted by an operon positively regulated by RpoS and contributes to adherence to epithelial cells in culture

Contact Info

Product

Resources

About