Type III secretion: what's in a name?

Institut National de la Recherche Agronomique, Centre de Recherche de Clermont-Ferrand-Theix, UR 454, Unité de Microbiologie, F-63122 Saint-Genès Champanelle, France.
Trends in Microbiology (Impact Factor: 9.81). 05/2006; 14(4):157-60. DOI: 10.1016/j.tim.2006.02.009
Source: PubMed

ABSTRACT The term 'type III secretion' has seen widespread use. However, problems persist in nomenclature. We propose that the standard abbreviation for this kind of secretion should be 'T3S' and that 'type III secretion system' should be abbreviated to 'T3SS'. There is also a need for a new terminology to distinguish flagellar and non-flagellar type III secretion systems that reflects their common evolutionary ancestry but does not obscure their distinctive features. Finally, the use of the term 'type III secretion' to cover cytolysin-mediated translocation is to be deprecated because an authentic type III secretion system has already been described in gram-positive bacteria, namely the flagellar protein export apparatus.

Download full-text


Available from: Michel Hébraud, Jul 28, 2015
  • Source
    • "In summary, these data indicate that the protein-specific residues within the amino-termini of FlaA and FlaB affect the level of protein secretion through the flagellum. As previously mentioned, the flagellum is a T3SS used to secrete flagellar structural components as well as effector proteins (Konkel et al., 1999, Konkel et al., 2004, Minamino & Namba, 2004, Desvaux et al., 2006). The mechanisms of T3S protein recognition and export are conserved between classical " injectisome " T3SS and flagellar T3SS, as it has been demonstrated that several proteins can be secreted through both systems. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Bacterial flagella play an essential role in the pathogenesis of numerous enteric pathogens. The flagellum is required for motility, colonization, and in some instances, for the secretion of effector proteins. In contrast to the intensively studied flagella of Escherichia coli and Salmonella typhimurium, the flagella of Campylobacter jejuni, Helicobacter pylori and Vibrio cholerae are less well characterized and composed of multiple flagellin subunits. This study was performed to gain a better understanding of flagellin export from the flagellar type III secretion apparatus of C. jejuni. The flagellar filament of C. jejuni is comprised of two flagellins termed FlaA and FlaB. We demonstrate that the amino-termini of FlaA and FlaB determine the length of the flagellum and motility of C. jejuni. We also demonstrate that protein-specific residues in the amino-terminus of FlaA and FlaB dictate export efficiency from the flagellar type III secretion system (T3SS) of Yersinia enterocolitica. These findings demonstrate that key residues within the amino-termini of two nearly identical proteins influence protein export efficiency, and that the mechanism governing the efficiency of protein export is conserved among two pathogens belonging to distinct bacterial classes. These findings are of additional interest because C. jejuni utilizes the flagellum to export virulence proteins.
    Molecular Microbiology 05/2010; 76(4):918-31. DOI:10.1111/j.1365-2958.2010.07144.x · 5.03 Impact Factor
  • Source
    • "Daarom wordt het PES beschouwd als een type van T3SS (Macnab 1999; Desvaux et al. 2006). Kortom, zelfs de flagel met het kleinste aantal verschillende eiwitten, kan verder ontmanteld worden tot nog eenvoudigere eiwitstructuren mét een functie, ook al is die functie dan eiwitsecretie i.p.v. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Irreducible complexity; intelligent design; intelligent ontwerp; creationisme; bacteriële flagel;
  • Source
    • "of an expansive family of highly conserved pore - forming toxins , known as cholesterol - dependent cytolysins ( TC #1 . C . 12 . ) ( Alouf , 2000 ) , permitting cytolysin - mediated translocation , in which a bacterial effector protein is translocated into the cytoplasm of an eukaryotic host cell ( Madden et al . , 2001 ; Meehl & Caparon , 2004 ; Desvaux et al . , 2006b ) . In Listeria , noncovalent binding of protein to bacterial cell - wall ( Des - vaux et al . , 2006a ) involves either ( 1 ) modules of around 80 amino acids containing the dipeptide glycine - tryptophan , i . e . modules GW , which interact with lipoteichoic acids , as found in InlB , and represents a total of nine predicted proteins"
    [Show abstract] [Hide abstract]
    ABSTRACT: Listeria monocytogenes, the etiologic agent of listeriosis, remains a serious public health concern with its frequent occurrence in food coupled with a high mortality rate. The capacity of a bacterium to secrete proteins to or beyond the bacterial cell surface is of crucial importance in the understanding of biofilm formation and bacterial pathogenesis to further develop defensive strategies. Recent findings in protein secretion in Listeria together with the availability of complete genome sequences of several pathogenic L. monocytogenes strains, as well as nonpathogenic Listeria innocua Clip11262, prompted us to summarize the listerial protein secretion systems. Protein secretion would rely essentially on the Sec (Secretion) pathway. The twin-arginine translocation pathway seems encoded in all but one sequenced Listeria. In addition, a functional flagella export apparatus, a fimbrilin-protein exporter, some holins and a WXG100 secretion system are encoded in listerial genomes. This critical review brings new insights into the physiology and virulence of Listeria species.
    FEMS Microbiology Reviews 10/2006; 30(5):774-805. DOI:10.1111/j.1574-6976.2006.00035.x · 13.81 Impact Factor
Show more