TY - JOUR
T1 - The Export of Coat Protein from Enteroaggregative Escherichia coli by a Specific ATP-binding Cassette Transporter System
AU - Nishi, Junichiro
AU - Sheikh, Jalaluddin
AU - Mizuguchi, Kenji
AU - Luisi, Ben
AU - Burland, Valerie
AU - Boutin, Adam
AU - Rose, Debra J.
AU - Blattner, Frederick R.
AU - Nataro, James P.
PY - 2003/11/14
Y1 - 2003/11/14
N2 - Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen characterized by aggregative adherence (AA) to cultured human mucosal epithelium cells. We have recently characterized a 10.2-kDa protein, called dispersin, which is exported from the bacteria and which promotes dispersal of EAEC across the intestinal mucosa. Here, we present evidence that dispersin is exported by a putative ABC transporter complex, which is encoded by a genetic locus of the EAEC virulence plasmid pAA2. We demonstrate that the locus comprises a cluster of five genes (designated aat-PABCD), including homologs of an inner-membrane permease (AatP), an ATP-binding cassette protein (AatC) and the outer membrane protein TolC (AatA). We show that, like TolC, AatA localizes to the outer membrane independently of its ABC partner. Dispersin appears to require the Aat complex for outer membrane translocation but not for secretion across the inner membrane. We also show that, like the dispersin gene, transcription of the aat cluster is dependent on AggR, a regulator of virulence genes in EAEC. We propose that the aat cluster encodes a specialized ABC transporter, which plays a role in the pathogenesis of EAEC by transporting dispersin out of the bacterial cell.
AB - Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen characterized by aggregative adherence (AA) to cultured human mucosal epithelium cells. We have recently characterized a 10.2-kDa protein, called dispersin, which is exported from the bacteria and which promotes dispersal of EAEC across the intestinal mucosa. Here, we present evidence that dispersin is exported by a putative ABC transporter complex, which is encoded by a genetic locus of the EAEC virulence plasmid pAA2. We demonstrate that the locus comprises a cluster of five genes (designated aat-PABCD), including homologs of an inner-membrane permease (AatP), an ATP-binding cassette protein (AatC) and the outer membrane protein TolC (AatA). We show that, like TolC, AatA localizes to the outer membrane independently of its ABC partner. Dispersin appears to require the Aat complex for outer membrane translocation but not for secretion across the inner membrane. We also show that, like the dispersin gene, transcription of the aat cluster is dependent on AggR, a regulator of virulence genes in EAEC. We propose that the aat cluster encodes a specialized ABC transporter, which plays a role in the pathogenesis of EAEC by transporting dispersin out of the bacterial cell.
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U2 - 10.1074/jbc.M306413200
DO - 10.1074/jbc.M306413200
M3 - Article
C2 - 12933818
AN - SCOPUS:0242664748
SN - 0021-9258
VL - 278
SP - 45680
EP - 45689
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 46
ER -