In addition to the CagA protein, bacterial cell wall components, such as peptidoglycan and heptose-1,7-bisphosphate, are also translocated via the T4SS
into host epithelial cells and recognized by the nucleotide-binding oligomerization domain receptor (NOD) and the TRAF-interacting protein with forkhead-associated domain (TIFA), respectively, to inducs NF-[kappa]B activation and up-regulation of pro-inflammatory immune responses (31,32).
T4SS is found in both gram-negative and gram-positive bacteria and in some archaea and allows the translocation of DNA and proteins into target cells, playing an important role in the pathogenesis of a wide range of bacteria .
amazonense strain 56AF, 7 out of the 13 T6SS-associated proteins (ImpA, ImpB, ImpC, ImpF, ImpG, ImpH, and ImpJ) were found, in addition to the T4SS homolog IcmF.
pylori expressing a functional T4SS
but not a non-functional T4SS
, activated NOD1 as assessed by reporter gene assays.
Unique region UR_26 represents the T4SS, which can deliver effector protein cancer-associated gene toxin (cagA) into gastric epithelial cells.
Abbreviations MALT: Mucosa-associated lymphoid tissue NPHS: Non-pylori Helicobacter species T4SS: Type IV secretion system cagA: Cancer-associated gene toxin VacA: Vacuolating cytotoxin ORFs: Open reading frames COGs: Clusters of Orthologous Groups VFDB: Virulence factor database NR: Nonredundant URHP: Unique regions of H.
(I) virB type IV secretion system (virB T4SS): In Brucella, T4SS is one of the main virulent factors and is encoded by the virB operon which contains totally 12 genes (VirB1-12) placed on chromosome II (de Jong and Tsolis, 2012).
Therefore, the T4SS plays a significant role for preventing host innate immune response and in stealthy intracellular survival during infection.
On the other hand, the T4SS
is a multiprotein complex that consists of a protein channel (encoded by virB and virD) through which proteins or protein-DNA complexes can be translocated between bacteria (cell-to-cell communication) and into host cells .
pVir is an [approximately equal to] 37.5-kb plasmid that contains components of a type IV secretion system (T4SS
) (15,16) known to be important for the virulence of a number of major bacterial pathogens (17).