N-terminal residues of SipB are required for its surface localization on Salmonella enterica serovar Typhimurium.
SipB, one of the invasion proteins encoded in Salmonella pathogenicity island 1 (SPI-1), is known to be secreted outside the cell, where it functions as a translocon by assembling into a host-cell plasma membrane-integral structure. Here, we confirmed that wild-type SipB could be localized to the bacterial outer membrane, and further showed that its localization was dependent on extracellular secretion, and was independent of the presence of the SipD protein. Proteinase K susceptibility and immunofluorescence assays indicated that SipB was not incorporated into the outer membrane, but rather was displayed on the bacterial surface. Finally, mutation studies revealed that the N-terminal 100-140 aa (especially amino acids 135-138) of SipB were required for its localization on the bacterial outer membrane.
Kim
Hyeon Guk
HG
Laboratory of Microbial Genetics, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
Kim
Bae Hoon
BH
Institute of Biotechnology, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea.|Laboratory of Microbial Genetics, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
Kim
Jin Seok
JS
Laboratory of Microbial Genetics, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
Eom
Jeong Seon
JS
Laboratory of Microbial Genetics, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
Bang
Iel-Soo
IS
Department of Microbiology and Immunology, Chosun University School of Dentistry, Gwang ju 501-759, Republic of Korea.
Bang
Seong Ho
SH
Department of Biological Science, Hanseo University, Seosan 356-706, Republic of Korea.
Lee
In Soo
IS
Department of Microbiology, Hannam University, DaeJeon 300-791, Republic of Korea.
Park
Yong Keun
YK
Laboratory of Microbial Genetics, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D019286:Endopeptidase K / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D012486:Salmonella typhimurium / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D008565:Membrane Proteins; C094579:invasion protein B, Salmonella typhimurium; D019286:Endopeptidase K