Table 2.
Effectors requiring the SPI-2-encoded T3SS for their translocation.
| Effector | Gene location | Selected homologues | Activity | Host cell target(s) | Role in infection |
|---|---|---|---|---|---|
| GogB | Bacteriophage Gifsy-1 | N-terminus: Yersinia YopM, Shigella IpaH7.8/9.8, Salmonella SspH1/2, SlrP. C-terminus: Yersinia YP2634/Y1471, rabbit EPEC OrfL, EHEC 0157:H7 Z1829 | |||
| PipB | SPI-5 | Salmonella PipB2 | |||
| PipB2 | Outside SPI-2 | Salmonella PipB | Kinesin-1 | Promotes Sif extension, recruits kinesin-1 to SCV | |
| SifA | Outside SPI-2 | Salmonella SifB | Rab mimic? | SKIP, Rab7/9 | Required for SCV membrane integrity & Sif formation, maintains perinuclear SCV positioning, redirects exocytic vesicles to SCV |
| SifB | Outside SPI-2 | Salmonella SifA | |||
| SopD2 | Outside SPI-2 | Salmonella SopD | Contributes to Sif formation, required for efficient bacterial replication in macrophages & mice | ||
| SpiC (SsaB) | SPI-2 | Hook 3, TassC | Interferes with vesicular trafficking, role in SCV-associated actin polymerisation (VAP) and Sif formation, controls order of protein export through SPI-2 T3SS | ||
| SseF | SPI-2 | Contributes to Sif formation, recruits dynein to SCV, maintains perinuclear SCV positioning, required for formation of microtubule bundles around SCV, redirects exocytic transport vesicles to SCV | |||
| SseG | SPI-2 | As SseF | |||
| SseI (SrfH/GtgB) | Bacteriophage Gifsy-2 | Filamin, TRIP6 | Remodels SCV associated F-actin? Promotes phagocyte motility | ||
| SseJ | Outside SPI-2 | Deacylase, phospholipase A & glycerol-phospholipid :cholesterol acyltransferase | Cholesterol | Negative regulation of Sifs, antagonises SifA SCV stabilisation | |
| SseK1 | Outside SPI-2 | Salmonella SseK2/3, Citrobacter rodentium NleB, EHEC Z4328 | |||
| SseK2 | Outside SPI-2 | Salmonella SseK1/3, Citrobacter rodentium NleB, EHEC Z4328 | |||
| SseK3 (NleB)a | ST64B coliform bacteriophage | Salmonella SseK1/2, Citrobacter rodentium NleB, EHEC Z4328 | |||
| SseL | Outside SPI-2 | Cysteine protease with deubiquitinase activity | IκBα | Macrophage apoptosis, downregulates inflammatory responses | |
| SspH2 | In vicinity of bacteriophage remnants | Salmonella SspH1, SlrP, GogB, Yersinia YopM, Shigella IpaH7.8/9.8 | Inhibits actin polymerisation in vitro | Filamin, Profilin | Remodels SCV associated F actin? |
| SteC (STM1698) | Outside SPI-2 | Eukaryotic kinases | Serine/Threonine kinase | Required for VAP | |
| SpvBb | pSLT (S. typhimurium) | N-terminus: Photorhabdus luminescens TcaC. N-terminus: Bacillus cereus VipB2, Clostridium botulinum C2 toxin component 1/C3 toxin, Clostridium perfringens Iota | ADP ribosyl transferase, inhibits actin polymerisation in vitro, depolymerises F-actin upon transfection | Actin | Inhibition of VAP, apoptosis of infected cells, required for full virulence in mice |
| SpvCb | pSLT (S. typhimurium) | Shigella OspF, Pseudomonas syringae HopAI1 | Phosphothreonine lyase | Required for full virulence in mice |
a
Found in S. typhimurium SL1344, not LT2.
b
Found in non-typhoid Salmonella serovars.