Deletion of the Riemerella anatipestifer type IX secretion system gene sprA results in differential expression of outer membrane proteins and virulence

2019 ◽  
Vol 48 (3) ◽  
pp. 191-203 ◽  
Author(s):  
Di Hu ◽  
Yunqing Guo ◽  
Jie Guo ◽  
Ying Wang ◽  
Zhe Pan ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Differential Expression ◽  
Outer Membrane Proteins ◽  
Secretion System ◽  
Riemerella Anatipestifer ◽  
Type Ix Secretion System

scholarly journals Differential Expression and Sequence Conservation of the Anaplasma marginale msp2 Gene Superfamily Outer Membrane Proteins

2006 ◽  
Vol 74 (6) ◽  
pp. 3471-3479 ◽  
Author(s):  
Susan M. Noh ◽  
Kelly A. Brayton ◽  
Donald P. Knowles ◽  
Joseph T. Agnes ◽  
Michael J. Dark ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Differential Expression ◽  
Outer Membrane Proteins ◽  
Anaplasma Marginale ◽  
Surface Proteins ◽  
Transcriptional Analysis ◽  
Mammalian Host ◽  
Anaplasma Ovis ◽  
Sequence Comparisons

ABSTRACT Bacterial pathogens in the genera Anaplasma and Ehrlichia encode a protein superfamily, pfam01617, which includes the predominant outer membrane proteins (OMPs) of each species, major surface protein 2 (MSP2) and MSP3 of Anaplasma marginale and Anaplasma ovis, Anaplasma phagocytophilum MSP2 (p44), Ehrlichia chaffeensis p28-OMP, Ehrlichia canis p30, and Ehrlichia ruminantium MAP1, and has been shown to be involved in both antigenic variation within the mammalian host and differential expression between the mammalian and arthropod hosts. Recently, complete sequencing of the A. marginale genome has identified an expanded set of genes, designated omp1-14, encoding new members of this superfamily. Transcriptional analysis indicated that, with the exception of the three smallest open reading frames, omp2, omp3, and omp6, these superfamily genes are transcribed in A. marginale-infected erythrocytes, tick midgut and salivary glands, and the IDE8 tick cell line. OMPs 1, 4, 7 to 9, and 11 were confirmed to be expressed as proteins by A. marginale within infected erythrocytes, with expression being either markedly lower (OMPs 1, 4, and 7 to 9) or absent (OMP11) in infected tick cells, which reflected regulation at the transcript level. Although the pfam01617 superfamily includes the antigenically variable MSP2 and MSP3 surface proteins, analysis of the omp1-14 sequences throughout a cycle of acute and persistent infection in the mammalian host and tick transmission reveals a high degree of conservation, an observation supported by sequence comparisons between the St. Maries strain and Florida strain genomes.

scholarly journals Proteomic analysis of Proteus mirabilis outer membrane proteins reveals differential expression in vivo vs. in vitro conditions

2011 ◽  
Vol 63 (2) ◽  
pp. 174-182 ◽  
Author(s):  
Bruno D'Alessandro ◽  
Leticia M. S. Lery ◽  
Wanda M. A. Krüger ◽  
Analía Lima ◽  
Claudia Piccini ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Differential Expression ◽  
Proteus Mirabilis ◽  
Proteomic Analysis ◽  
Outer Membrane Proteins

scholarly journals Virulence Factors in Hypervirulent Klebsiella pneumoniae

2021 ◽  
Vol 12 ◽  
Author(s):  
Jie Zhu ◽  
Tao Wang ◽  
Liang Chen ◽  
Hong Du
Keyword(s):  
Membrane Proteins ◽  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Virulence Factors ◽  
Outer Membrane Proteins ◽  
Pyogenic Liver Abscess ◽  
Secretion System ◽  
Asian Pacific ◽  
Shed Light ◽  
New Strategies

Hypervirulent Klebsiella pneumoniae (hvKP) has spread globally since first described in the Asian Pacific Rim. It is an invasive variant that differs from the classical K. pneumoniae (cKP), with hypermucoviscosity and hypervirulence, causing community-acquired infections, including pyogenic liver abscess, pneumonia, meningitis, and endophthalmitis. It utilizes a battery of virulence factors for survival and pathogenesis, such as capsule, siderophores, lipopolysaccharide, fimbriae, outer membrane proteins, and type 6 secretion system, of which the former two are dominant. This review summarizes these hvKP-associated virulence factors in order to understand its molecular pathogenesis and shed light on new strategies to improve the prevention, diagnosis, and treatment of hvKP-causing infection.

scholarly journals Roles of OmpA in Type III Secretion System-Mediated Virulence of Enterohemorrhagic Escherichia coli

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1496
Author(s):  
Hidetada Hirakawa ◽  
Kazutomo Suzue ◽  
Ayako Takita ◽  
Haruyoshi Tomita
Keyword(s):  
Escherichia Coli ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Type Iii Secretion ◽  
Parent Strain ◽  
Outer Membrane Proteins ◽  
Type Iii Secretion System ◽  
Bacterial Pathogenesis ◽  
Secretion System ◽  
Enterohemorrhagic Escherichia Coli

Outer membrane proteins are commonly produced by gram-negative bacteria, and they have diverse functions. A subgroup of proteins, which includes OmpA, OmpW and OmpX, is often involved in bacterial pathogenesis. Here we show that OmpA, rather than OmpW or OmpX, contributes to the virulence of enterohemorrhagic Escherichia coli (EHEC) through its type III secretion system (T3SS). Deletion of ompA decreased secretion of the T3SS proteins EspA and EspB; however, the expression level of the LEE genes that encode a set of T3SS proteins did not decrease. The ompA mutant had less abilities to form A/E lesions in host epithelial cells and lyse human red blood cells than the parent strain. Moreover, the virulence of an ompA mutant of Citrobacter rodentium (traditionally used to estimate T3SS-associated virulence in mice) was attenuated. Mice infected with the ompA mutant survived longer than those infected with the parent strain. Furthermore, mice infected with ompA developed symptoms of diarrhea more slowly than mice infected with the parent strain. Altogether, these results suggest that OmpA sustains the activity of the T3SS and is required for optimal virulence in EHEC. This work expands the roles of outer membrane proteins in bacterial pathogenesis.

scholarly journals A putative multicopper protein secreted by an atypical type II secretion system involved in the reduction of insoluble electron acceptors in Geobacter sulfurreducens

Microbiology ◽  
2006 ◽  
Vol 152 (8) ◽  
pp. 2257-2264 ◽  
Author(s):  
Teena Mehta ◽  
Susan E. Childers ◽  
Richard Glaven ◽  
Derek R. Lovley ◽  
Tünde Mester
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Secretion System ◽  
Geobacter Sulfurreducens ◽  
Extracellular Electron Transfer ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Oxide Reduction ◽  
Type Ii Secretion System

Extracellular electron transfer onto Fe(III) oxides in Geobacter sulfurreducens is considered to require proteins that must be exported to the outer surface of the cell. In order to investigate this, the putative gene for OxpG, the pseudopilin involved in a type II general secretion pathway of Gram-negative bacteria, was deleted. The mutant was unable to grow with insoluble Fe(III) oxide as the electron acceptor. Growth on soluble Fe(III) was not affected. An analysis of proteins that accumulated in the periplasm of the oxpG mutant, but not in the wild-type, led to the identification of a secreted protein, OmpB. OmpB is predicted to be a multicopper protein, with highest homology to the manganese oxidase, MofA, from Leptothrix discophora. OmpB contains a potential Fe(III)-binding site and a fibronectin type III domain, suggesting a possible role for this protein in accessing Fe(III) oxides. OmpB was localized to the membrane fraction of G. sulfurreducens and in the supernatant of growing cultures, consistent with the type II secretion system exporting OmpB. A mutant in which ompB was deleted had the same phenotype as the oxpG mutant, suggesting that the failure to export OmpB was responsible for the inability of the oxpG-deficient mutant to reduce Fe(III) oxide. This is the first report that proposes a role for a multicopper oxidase-like protein in an anaerobic organism. These results further emphasize the importance of outer-membrane proteins in Fe(III) oxide reduction and suggest that outer-membrane proteins other than c-type cytochromes are required for Fe(III) oxide reduction in Geobacter species.

scholarly journals Characterization of a Predominant Immunogenic Outer Membrane Protein of Riemerella anatipestifer

2000 ◽  
Vol 7 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Sumathi Subramaniam ◽  
Bin Huang ◽  
Hilda Loh ◽  
Jimmy Kwang ◽  
Hai-Meng Tan ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Calcium Binding ◽  
Outer Membrane Proteins ◽  
Terminal Region ◽  
Gene Encoding ◽  
Riemerella Anatipestifer ◽  
Binding Domains

ABSTRACT The ompA gene, encoding the 42-kDa major antigenic outer membrane protein OmpA of Riemerella anatipestifer, the etiololgical agent of septicemia anserum exsudativa, was cloned and expressed in Escherichia coli. Recombinant OmpA displayed a molecular mass similar to that predicted from the nucleotide sequence of the ompA gene but lower than that observed in total cell lysates of R. anatipestifer. The ompA gene showed a conserved C-terminal region comprising the OmpA-like domain and a variable N-terminal region. This structure is similar to those of the analogous outer membrane proteins of several gram-negative bacteria. However, OmpA of R. anatipestifercontains six EF-hand calcium-binding domains and two PEST regions, which distinguish it from other outer membrane proteins. The occurrence of these motifs in OmpA suggests a possible role in virulence for this protein. The ompA gene is present in the R. anatipestifer type strain and in all serotype reference strains. However, it exhibits some minor genetic heterogeneity among different serotypes, which seems not to affect the strong antigenic characteristics of the protein. OmpA is a conserved and strong antigenic determinant of R. anatipestifer and hence is suggested to be a valuable protein for the serodetection of R. anatipestifer infections, independent of their serotype.

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