. 2009 Feb;12(1-3):101–109. doi: 10.1016/j.mib.2008.11.006

Table 1.

The effector repertoire of EPEC 2348/69 and known functional characteristics of effector proteins.

EPEC effector	Island location	Cellular/physiological functions	Subcellular target sites	Proposed host partners	Functional motifs	Homologue family
Tir	LEE	Actin polymerisation	Plasma membrane	IQGAP1	SH3-binding domains	None known
		TJ disruption^a	Cytoplasm	14-3-3tau	GAP motif
		Cell detachment		Nck	Phos. sites
		Microvilli effacement		α-Actinin
		SGLT-1 inactivation		Talin
		PLCγ phosphorylation		Cortactin
		Regulating effector activity^a		Vinculin
		Invasion non-polarised cells		Cytokeratin 18

Map	LEE	TJ disruption	Mitochondria	EBP50/	PDZ1-binding domain	IpgB2
		Filopodia formation	Actin^a	NHERF1	MTS
		Mitochondrial dysfunction	Cytoplasm		WxxxE
		Microvilli effacement
		SGLT-1 inactivation
		Invasion non-polarised cells

EspB	LEE	Anti-phagocytosis	Cytoplasm	Antitrypsin		YopD
		Microvilli effacement	Plasma membrane	α-Catenin
		Actin disruption		Myosin
		Pore formation

EspF	LEE	Apoptosis	Mitochondria, cytoplasm	ABCF2	PRR,	None known except other EspF variants such as EspF(U)
		TJ disruption	Apical and lateral membranes	Actin	SH3
		Microvilli effacement	TJ region^a	ZO-1/ZO-2	N-WASP and SNX9 binding domains
		Microvilli elongation		Profilin	MTS
		SGLT-1 inactivation		Arp2/3
		Mitochondrial dysfunction		Cytokeratin18
		Pedestal maturation		Sorting nexin 9
		Inhibition of NHE3 activity		N-WASP
		Membrane remodelling		14-3-3
		Aquaporin redistribution		Mito protein^b
		N-WASP activation

EspH	LEE	Modulating actin dynamics	Pedestals			None known
		Cytoskeleton disruption	Plasma membrane

EspZ	LEE	Unknown	Pedestals			None known

EspG	LEE	Microtubule disruption	Microtubule colocalisation	Tubulin		VirA
		TJ disruption
		Paracellular permeability
		Aquaporin redistribution
		Stress fibres formation
		DRA transporter inhibition

NleH1	PP2	Pro-inflammatory				OspG
EspJ	PP2	Anti-phagocytosis				None known
NleB2	PP4	Unknown				None known
NleC	PP4	Unknown				AIP56^c
NleD	PP4	Unknown				HopAP1, HopH1^d
NleG	PP4	Unknown				None
NleH2	PP6	Pro-inflammatory				OspG
NleF	PP6	Unknown				None

NleA	PP6	Inhibition of protein secretion by interference	Golgi	Sec24	PDZ1	None known
(EspI)		with COPII		PDZK11
				SNX27
				MAlS3
				TCOF1^b

NleE2	IE2	PMN transepithelial migration	Nucleus			OspZ
EspG2/Orf3	IE5	As with EspG				VirA
NleB1	IE6	Unknown				None known
NleE1	IE6	PMN trans-epithelial migration	Nucleus			OspZ
EspL2	IE6	Unknown				OspD^e
EspL1	IE2	Pseudogene (see Figure 3)
NleB3	IE2	Pseudogene (see Figure 3)
EspO	PP6	Pseudogene (see Figure 3)
Cif	PP2	Pseudogene (see Figure 3)
NleH3	PP4	Pseudogene (see Figure 3)

The predicted set of EPEC effectors comprises 21 full-length genes and at least 5 identified pseudogenes (i.e. genes truncated by stop codons, missing start codons, containing frameshift mutations). Where more than one copy of an effector exists, genes are numbered in accordance with sequence comparison to known EHEC homologues. For example, the full-length gene EspL is more similar to EHEC EspL2, whilst the EspL pseudogene corresponds with EspL1 and is named accordingly. All effectors are found on the chromosome in pathogenicity islands specified in [6^•] and illustrated in Figure 3. We have attempted to include all the known and documented effector functions and the known subcellular locations from published sources. ‘Homologue family’ gives an example of a known homologue from an effector family; where indicated as ‘none known’ this does not discount similarities with unassigned hypothetical proteins. Island location is illustrated in Figure 3 in accordance with [6^•]. All other references can be found in the text or in [3]. Phos, phosphorylation; MTS, mitochondrial targeting sequence; PRR, proline-rich repeat; SH3, src homology domains; PMN, polymorphonuclear; TJ, tight junction; IQGAP, IQ motif containing GTPase activating protein; EBP50/NHERF1, Na⁺/H⁺ exchanger regulating factor 1; ezrin–radixin–moesin, ERM-binding phosphoprotein of 50 kDa.

We have attempted to include all the known and documented effector functions and the known subcellular locations from unpublished sources.

‘Functional motifs’ and ‘proposed host partners’ correspond to those that have been proved to have functional significance, although in some cases, data from yeast two-hybrid protein–protein interactions are included as in [49,50].

Photobacterium virulence protein.

Pseudomonas syringae effector proteins.

Also has Shiglella enterotoxin homology.