TABLE 1.

SPI-1 and SPI-2 effectors that contribute to the intracellular lifecycle of S. Typhimurium

Effector	Secretion system	Cellular target	Biochemical activity	Biological function	References
SopE/E2	SPI-1	Cdc42 and Rac1	GEF	SCV formation	13–18
SopB	SPI-1	PI(4,5)P2	Phosphatidylinositol phosphatase	SCV formation, maturation, and avoidance of lysosomal degradation	19–23, 35, 36
GtgE	SPI-1	Rab32	Cysteine protease	SCV avoidance of lysosomal degradation	29–34
SopD2	SPI-2	Rab32, Rab7	GAP	SCV avoidance of lysosomal degradation	28, 34
SseG	SPI-2	GCP60/ACBD3	Unknown	SCV perinuclear positioning	26, 37, 39, 40
SseF	SPI-2	GCP60/ACBD3	Unknown	SCV perinuclear positioning	37–40
SifA	SPI-2	SKIP	Unknown	SCV perinuclear positioning, Sif formation, SCV integrity	43, 44, 48, 49, 52–54, 58, 59
SipA	SPI-1	Actin	Actin polymerization,	SCV perinuclear positioning	45–48
PipB2	SPI-2	Kinesin-1	Unknown	Sif formation	42–44, 48, 52, 53
SptP	SPI-1	Valosin-containing protein	Phosphatase	Sif formation	55–57
SseJ	SPI-2	Cholesterol, RhoA	Glycerophospholipid: cholesterol acyltransferase	SCV and Sif membrane dynamics	60–67
SteA	SPI-1, SPI-2	Unknown	Unknown	SCV and Sif membrane dynamics	68–71
SteC	SPI-2	MEK1	Kinase	SCV-surrounding actin meshwork	73, 74
SpvB	SPI-2	G-actin	ADP-ribosylating protein	SCV-surrounding actin meshwork	75–77