The enteropathogenic E. coli effector EspB facilitates microvillus effacing and antiphagocytosis by inhibiting myosin function.
Enteropathogenic Escherichia coli (EPEC) destroys intestinal microvilli and suppresses phagocytosis by injecting effectors into infected cells through a type III secretion system (TTSS). EspB, a component of the TTSS, is also injected into the cytoplasm of host cells. However, the physiological functions of EspB within the host cell cytoplasm remain unclear. We show that EspB binds to myosins, which are a superfamily of proteins that interact with actin filaments and mediate essential cellular processes, including microvillus formation and phagocytosis. EspB inhibits the interaction of myosins with actin, and an EspB mutant that lacks the myosin-binding region maintained its TTSS function but could not induce microvillus effacing or suppress phagocytosis. Moreover, the myosin-binding region of EspB is essential for Citrobacter rodentium, an EPEC-related murine pathogen, to efficiently infect mice. These results suggest that EspB inhibits myosin functions and thereby facilitates efficient infection by EPEC.
Iizumi
Yosuke
Y
Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
Sagara
Hiroshi
H
Kabe
Yasuaki
Y
Azuma
Motoki
M
Kume
Kanako
K
Ogawa
Michinaga
M
Nagai
Takeshi
T
Gillespie
Peter G
PG
Sasakawa
Chihiro
C
Handa
Hiroshi
H
D000199:Actins / Q000037:antagonists & inhibitors / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018938:Caco-2 Cells; D044082:Citrobacter rodentium / Q000737:chemistry / Q000472:pathogenicity; D054308:Enteropathogenic Escherichia coli / Q000737:chemistry / Q000378:metabolism* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology; D051379:Mice; D008809:Mice, Inbred C3H; D008871:Microvilli / Q000378:metabolism / Q000382:microbiology; D008969:Molecular Sequence Data; D009218:Myosins / Q000378:metabolism*; D010587:Phagocytosis; D011485:Protein Binding; D016415:Sequence Alignment; D014774:Virulence
D000199:Actins; D001425:Bacterial Outer Membrane Proteins; C087863:EaeB protein, E coli; D029968:Escherichia coli Proteins; D009218:Myosins