title: Bacterial guanine nucleotide exchange factors SopE-like and WxxxE effectors.
abstract: Subversion of Rho family small GTPases, which control actin dynamics, is a common infection strategy used by bacterial pathogens. In particular, Salmonella enterica serovar Typhimurium, Shigella flexneri, enteropathogenic Escherichia coli (EPEC), and enterohemorrhagic Escherichia coli (EHEC) translocate type III secretion system (T3SS) effector proteins to modulate the Rho GTPases RhoA, Cdc42, and Rac1, which trigger formation of stress fibers, filopodia, and lamellipodia/ruffles, respectively. The Salmonella effector SopE is a guanine nucleotide exchange factor (GEF) that activates Rac1 and Cdc42, which induce "the trigger mechanism of cell entry." Based on a conserved Trp-xxx-Glu motif, the T3SS effector proteins IpgB1 and IpgB2 of Shigella, SifA and SifB of Salmonella, and Map of EPEC and EHEC were grouped together into a WxxxE family; recent studies identified the T3SS EPEC and EHEC effectors EspM and EspT as new family members. Recent structural and functional studies have shown that representatives of the WxxxE effectors share with SopE a 3-D fold and GEF activity. In this minireview, we summarize contemporary findings related to the SopE and WxxxE GEFs in the context of their role in subverting general host cell signaling pathways and infection.
authors.affiliation: Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Bulgin
authors.forename: Benoit
authors.initials: B
authors.lastname: Raymond
authors.forename: James A
authors.initials: JA
authors.lastname: Garnett
authors.forename: Gad
authors.initials: G
authors.lastname: Frankel
authors.forename: Valerie F
authors.initials: VF
authors.lastname: Crepin
authors.forename: Cedric N
authors.initials: CN
authors.lastname: Berger
authors.forename: Ana
authors.initials: A
authors.lastname: Arbeloa
mesh_terms: D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism*; D004755:Enterobacteriaceae / Q000472:pathogenicity*; D029968:Escherichia coli Proteins / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D037521:Virulence Factors / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: D000199:Actins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006023:Glycoproteins; D020662:Guanine Nucleotide Exchange Factors; C512346:Map protein, E coli; C421862:SifA protein, Salmonella; C103987:SopE protein, Salmonella; D037521:Virulence Factors; C543137:espM protein, E coli; C543138:espT protein, E coli; C508203:IpgB1 protein, Shigella flexneri; C508202:IpgB2 protein, Shigella flexneri; D020830:rac1 GTP-Binding Protein