Affiliation:
1. Department of Biological Sciences, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin, USA
Abstract
ABSTRACT
Flavobacterium johnsoniae
exhibits gliding motility and digests many polysaccharides, including chitin. A novel protein secretion system, the type IX secretion system (T9SS), is required for gliding and chitin utilization. The T9SS secretes the cell surface motility adhesins SprB and RemA and the chitinase ChiA. Proteins involved in secretion by the T9SS include GldK, GldL, GldM, GldN, SprA, SprE, and SprT.
Porphyromonas gingivalis
has orthologs for each of these that are required for secretion of gingipain protease virulence factors by its T9SS.
P. gingivalis
porU
and
porV
have also been linked to T9SS-mediated secretion, and
F. johnsoniae
has orthologs of these. Mutations in
F. johnsoniae
porU
and
porV
were constructed to determine if they function in secretion. Cells of a
porV
deletion mutant were deficient in chitin utilization and failed to secrete ChiA. They were also deficient in secretion of the motility adhesin RemA but retained the ability to secrete SprB. SprB is involved in gliding motility and is needed for formation of spreading colonies on agar, and the
porV
mutant exhibited gliding motility and formed spreading colonies. However, the
porV
mutant was partially deficient in attachment to glass, apparently because of the absence of RemA and other adhesins on the cell surface. The
porV
mutant also appeared to be deficient in secretion of numerous other proteins that have carboxy-terminal domains associated with targeting to the T9SS. PorU was not required for secretion of ChiA, RemA, or SprB, indicating that it does not play an essential role in the
F. johnsoniae
T9SS.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Cited by
69 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献