Sm. Jin et al., JlpA, a novel surface-exposed lipoprotein specific to Campylobacter jejuni, mediates adherence to host epithelial cells, MOL MICROB, 39(5), 2001, pp. 1225-1236
A 1116 bp open reading frame (ORF), designated jlpA, encoding a novel speci
es-specific lipoprotein of Campylobacter jejuni TGH9011, was identified fro
m recombinant plasmid pHIP-O. The jlpA gene encodes a polypeptide (JlpA) of
372 amino acid residues with a molecular mass of 42.3 kDa. JlpA contains a
typical signal peptide and lipoprotein processing site at the N-terminus.
The presence of a lipid moiety on the JlpA molecule was confirmed by the in
corporation of [H-3]-palmitic acid. Immunoblotting analysis of cell surface
extracts prepared using glycine-acid buffer (pH 2.2) and proteinase K dige
stion of whole cells indicated that JlpA is a surface-exposed lipoprotein i
n C. jejuni. JlpA is loosely associated with the cell surface, as it is eas
ily extracted from the C. jejuni outer membrane by detergents, such as sarc
osyl and Triton X-100. JlpA is released to the culture medium, and its conc
entration increases in a time-dependent fashion. The adherence of both inse
rtion and deletion mutants of jlpA to HEp-2 epithelial cells was reduced co
mpared with that of parental C. jejuni TGH9011. Adherence of C. jejuni to H
Ep-2 cells was inhibited in a dose-dependent manner when the bacterium was
preincubated with anti-GST-JlpA antibodies or when HEp-2 cells were preincu
bated with JlpA protein. A ligand-binding immunoblotting assay showed that
JlpA binds to HEp-2 cells, which suggests that JlpA is C. jejuni adhesin.