TY - JOUR
T1 - Biogenesis of Salmonella enterica serovar typhimurium membrane vesicles provoked by induction of PagC
AU - Kitagawa, Ryo
AU - Takaya, Akiko
AU - Ohya, Mai
AU - Mizunoe, Yoshimitsu
AU - Takade, Akemi
AU - Yoshida, Shin Ichi
AU - Isogai, Emiko
AU - Yamamoto, Tomoko
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2010/11
Y1 - 2010/11
N2 - Gram-negative bacteria ubiquitously release membrane vesicles (MVs) into the extracellular milieu. Although MVs are the product of growing bacteria, not of cell lysis or death, the regulatory mechanisms underlying MV formation remained unknown. We have found that MV biogenesis is provoked by the induction of PagC, a Salmonella-specific protein whose expression is activated by conditions that mimic acidified macrophage phagosomes. PagC is a major constituent of Salmonella MVs, and increased expression accelerates vesiculation. Expression of PagC is regulated at the posttranscriptional and/or posttranslational level in a sigmaS (RpoS)-dependent manner. Serial quantitative analysis has demonstrated that MV formation can accelerate when the quantity of the MV constituents, OmpX and PagC, rises. Overproduction of PagC dramatically impacts the difference in the relative amount of vesiculation, but the corresponding overproduction of OmpX was less pronounced. Quantitative examination of the ratios of PagC and OmpX in the periplasm, outer membrane, and MVs demonstrates that PagC is preferentially enriched in MVs released from Salmonella cells. This suggests that specific protein sorting mechanisms operate when MVs are formed. The possible role(s) of PagC-MV in host cells is discussed.
AB - Gram-negative bacteria ubiquitously release membrane vesicles (MVs) into the extracellular milieu. Although MVs are the product of growing bacteria, not of cell lysis or death, the regulatory mechanisms underlying MV formation remained unknown. We have found that MV biogenesis is provoked by the induction of PagC, a Salmonella-specific protein whose expression is activated by conditions that mimic acidified macrophage phagosomes. PagC is a major constituent of Salmonella MVs, and increased expression accelerates vesiculation. Expression of PagC is regulated at the posttranscriptional and/or posttranslational level in a sigmaS (RpoS)-dependent manner. Serial quantitative analysis has demonstrated that MV formation can accelerate when the quantity of the MV constituents, OmpX and PagC, rises. Overproduction of PagC dramatically impacts the difference in the relative amount of vesiculation, but the corresponding overproduction of OmpX was less pronounced. Quantitative examination of the ratios of PagC and OmpX in the periplasm, outer membrane, and MVs demonstrates that PagC is preferentially enriched in MVs released from Salmonella cells. This suggests that specific protein sorting mechanisms operate when MVs are formed. The possible role(s) of PagC-MV in host cells is discussed.
UR - http://www.scopus.com/inward/record.url?scp=78049408647&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78049408647&partnerID=8YFLogxK
U2 - 10.1128/JB.00590-10
DO - 10.1128/JB.00590-10
M3 - Article
C2 - 20802043
AN - SCOPUS:78049408647
VL - 192
SP - 5645
EP - 5656
JO - Journal of Bacteriology
JF - Journal of Bacteriology
SN - 0021-9193
IS - 21
ER -