Structural alterations in a type IV pilus subunit protein result in concurrent defects in multicellular behaviour and adherence to host tissue

Citation
Hsm. Park et al., Structural alterations in a type IV pilus subunit protein result in concurrent defects in multicellular behaviour and adherence to host tissue, MOL MICROB, 42(2), 2001, pp. 293-307
Citations number
45
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
MOLECULAR MICROBIOLOGY
ISSN journal
0950-382X → ACNP
Volume
42
Issue
2
Year of publication
2001
Pages
293 - 307
Database
ISI
SICI code
0950-382X(200110)42:2<293:SAIATI>2.0.ZU;2-U
Abstract
The ability of bacteria to establish complex communities on surfaces is bel ieved to require both bacterial-substratum and bacterial-bacterial interact ions, and type IV pill appear to play a critical but incompletely defined r ole in both these processes. Using the human pathogen Neisseria gonorrhoeae , spontaneous mutants defective in bacterial self-aggregative behaviour but quantitatively unaltered in pilus fibre expression were isolated by a uniq ue selective scheme. The mutants, carrying single amino acid substitutions within the conserved aminoterminal domain of the pilus fibre subunit, were reduced in the ability to adhere to a human epithelial cell line. Co-expres sion of the altered alleles in the context of a wild-type pilE gene confirm ed that they were dominant negative with respect to aggregation and human c ell adherence. Strains expressing two copies of the altered alleles produce d twice as much purifiable pili but retained the aggregative and adherence defects. Finally, the defects in aggregative behaviour and adherence of eac h of the mutants were suppressed by a loss-of-function mutation in the twit ching motility gene pilT. The correlations between self-aggregation and the net capacity of the microbial population to adhere efficiently demonstrate s the potential significance of bacterial cell-cell interactions to coloniz ation.