Surface proteins of group G Streptococcus in different phases of growth: patterns of production and implications for the host-bacteria relationship.
Group G Streptococcus (GGS) is a human bacterial pathogen expressing surface proteins FOG and protein G (PG) which interact with several host defence systems, including the complement and contact systems. Selected reaction monitoring mass spectrometry, electron microscopy and protein binding assays were used to track the amounts of FOG and PG intracellularly and on the bacterial surface during different phases of growth. Large and increasing amounts of PG were present on the surface in the stationary growth phase, and this was due to de novo production. In contrast, the amount of FOG did not change substantially during this phase. Apart from PG, a number of housekeeping proteins also increased in abundance in the stationary phase. These results show that GGS protein production is active during the stationary phase and that the bacteria actively remodel their surface and enter a less pro-inflammatory state in this phase.
Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden.
Kristofer
K
Wollein Waldetoft
Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden.
Christofer
C
Karlsson
Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden.
Magnus
M
Gram
Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden.
Johan
J
Malmström
Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden.
Matthias
M
Mörgelin
Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden.
Inga-Maria
IM
Frick
Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden.
Lars
L
Björck
D001426:Bacterial Proteins / Q000032:analysis*; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000032:analysis*; D008854:Microscopy, Electron; D013291:Streptococcus / Q000737:chemistry* / Q000254:growth & development*
D001426:Bacterial Proteins; D008565:Membrane Proteins