title: A bacterial effector targets Mad2L2, an APC inhibitor, to modulate host cell cycling.
abstract: The gut epithelium self-renews every several days, providing an important innate defense system that limits bacterial colonization. Nevertheless, many bacterial pathogens, including Shigella, efficiently colonize the intestinal epithelium. Here, we show that the Shigella effector IpaB, when delivered into epithelial cells, causes cell-cycle arrest by targeting Mad2L2, an anaphase-promoting complex/cyclosome (APC) inhibitor. Cyclin B1 ubiquitination assays revealed that APC undergoes unscheduled activation due to IpaB interaction with the APC inhibitor Mad2L2. Synchronized HeLa cells infected with Shigella failed to accumulate Cyclin B1, Cdc20, and Plk1, causing cell-cycle arrest at the G2/M phase in an IpaB/Mad2L2-dependent manner. IpaB/Mad2L2-dependent cell-cycle arrest by Shigella infection was also demonstrated in rabbit intestinal crypt progenitors, and the IpaB-mediated arrest contributed to efficient colonization of the host cells. These results strongly indicate that Shigella employ special tactics to influence epithelial renewal in order to promote bacterial colonization of intestinal epithelium.
authors: Department of Microbiology and Immunology, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors: Hiroki
authors: H
authors: Iwai
authors: Minsoo
authors: M
authors: Kim
authors: Yuko
authors: Y
authors: Yoshikawa
authors: Hiroshi
authors: H
authors: Ashida
authors: Michinaga
authors: M
authors: Ogawa
authors: Yukihiro
authors: Y
authors: Fujita
authors: Daniel
authors: D
authors: Muller
authors: Teruo
authors: T
authors: Kirikae
authors: Peter K
authors: PK
authors: Jackson
authors: Shuji
authors: S
authors: Kotani
authors: Chihiro
authors: C
authors: Sasakawa
mesh_terms: D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000502:physiology; D002455:Cell Division; D004405:Dysentery, Bacillary / Q000473:pathology; D016195:G2 Phase; D005982:Glutathione Transferase / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007082:Ileum / Q000382:microbiology; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000382:microbiology; D064246:Mad2 Proteins; D008954:Models, Biological; D011233:Precipitin Tests; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D011817:Rabbits; D011994:Recombinant Proteins / Q000378:metabolism; D012760:Shigella / Q000378:metabolism* / Q000472:pathogenicity; D020798:Two-Hybrid System Techniques; D043743:Ubiquitin-Protein Ligase Complexes / Q000037:antagonists & inhibitors*; D014452:Ubiquitins / Q000032:analysis
chemical_list: D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; C120552:MAD2L2 protein, human; D064246:Mad2 Proteins; D018809:Proliferating Cell Nuclear Antigen; D011506:Proteins; D011994:Recombinant Proteins; D014452:Ubiquitins; C087447:ipaB protein, Shigella; D049452:Green Fluorescent Proteins; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D005982:Glutathione Transferase