TY - JOUR
T1 - Identification of a Salmonella virulence gene required for formation of filamentous structures containing lysosomal membrane glycoproteins within epithelial cells
AU - Stein, Murry A.
AU - Leung, Ka Yin
AU - Zwick, Michael
AU - Garcia-del Portillo, Francisco
AU - Finlay, B. Brett
PY - 1996
Y1 - 1996
N2 - Salmonella species are facultative intracellular pathogens that invade epithelial cells and reside within lysosomal membrane glycoprotein (Igp)-containing vacuoles. Coincident with the onset of bacterial replication inside these vacuoles, Salmonella induce the formation of stable Igp-containing filamentous structures that connect with the Salmonella-containing vacuoles. Salmonella typhimurium SL1344::Tn 10dCm mutant strains unable to induce these structures were isolated. All contained insertions within a novel Salmonella induced filament gene A (sifA). sifA is present only in Salmonella species and encodes a protein with a predicted molecular mass of 38 kDa and an apparent molecular mass of 35 kDa. sifA is flanked by ~300 base pairs, and sifA and its flanking DNA show no homology to sequences in DNA databases. sifA is located within the potABCD operon, a housekeeping locus involved in periplasmic transport of polyamines. Fourteen-base-pair direct repeats mark the probable site of integration of sifA and its flanking DNA at the 3' end of potB. sifA and its flanking DNA have a significantly reduced G+C content (41%) when compared with the potABCD operon (51%) and the Salmonella genome (52-54%). Deletion mutant strains in sifA or in the downstream potC were constructed. ΔsifA does not produce Salmonella-induced filaments in epithelial oells, and is attenuated in mice. ΔpotC produces Salmonella-induced filaments in epithelial cells, and was fully virulent. Collectively, these results suggest that sifA arose by horizontal gene transfer into Salmonella and its product is involved in a virulence-associated intracellular phenotype related to Salmonella-induced filament formation.
AB - Salmonella species are facultative intracellular pathogens that invade epithelial cells and reside within lysosomal membrane glycoprotein (Igp)-containing vacuoles. Coincident with the onset of bacterial replication inside these vacuoles, Salmonella induce the formation of stable Igp-containing filamentous structures that connect with the Salmonella-containing vacuoles. Salmonella typhimurium SL1344::Tn 10dCm mutant strains unable to induce these structures were isolated. All contained insertions within a novel Salmonella induced filament gene A (sifA). sifA is present only in Salmonella species and encodes a protein with a predicted molecular mass of 38 kDa and an apparent molecular mass of 35 kDa. sifA is flanked by ~300 base pairs, and sifA and its flanking DNA show no homology to sequences in DNA databases. sifA is located within the potABCD operon, a housekeeping locus involved in periplasmic transport of polyamines. Fourteen-base-pair direct repeats mark the probable site of integration of sifA and its flanking DNA at the 3' end of potB. sifA and its flanking DNA have a significantly reduced G+C content (41%) when compared with the potABCD operon (51%) and the Salmonella genome (52-54%). Deletion mutant strains in sifA or in the downstream potC were constructed. ΔsifA does not produce Salmonella-induced filaments in epithelial oells, and is attenuated in mice. ΔpotC produces Salmonella-induced filaments in epithelial cells, and was fully virulent. Collectively, these results suggest that sifA arose by horizontal gene transfer into Salmonella and its product is involved in a virulence-associated intracellular phenotype related to Salmonella-induced filament formation.
UR - http://www.scopus.com/inward/record.url?scp=0029864857&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2958.1996.tb02497.x
DO - 10.1111/j.1365-2958.1996.tb02497.x
M3 - 文章
C2 - 8861213
AN - SCOPUS:0029864857
SN - 0950-382X
VL - 20
SP - 151
EP - 164
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 1
ER -