Journal article
Identification of a Pneumococcal Glycosidase That Modifies O-Linked Glycans
Infection and immunity, Vol.77(4), pp.1389-1396
04/2009
DOI: 10.1128/IAI.01215-08
PMCID: PMC2663135
PMID: 19139197
Abstract
Colonization of the airway by
Streptococcus pneumoniae
is typically asymptomatic; however, progression of bacteria beyond the oronasopharynx can cause diseases including otitis media and pneumonia. The mechanisms by which
S. pneumoniae
establishes and maintains colonization remain poorly understood. Both N-linked and O-linked glycans are abundant in the airway. Our previous research demonstrated that
S. pneumoniae
can sequentially deglycosylate N-linked glycans and suggested that this modification of sugar structures may aid in colonization. There is published evidence that
S. pneumoniae
expresses a secreted O-glycosidase that cleaves galactose β1-3
N
-acetylgalactosamine (Galβ1-3GalNAc) from core-1 O-linked glycans; however, the biological function of this enzyme has not previously been determined. We established that the activity is not secreted but is instead surface associated in a sortase-dependent manner. Genome analysis revealed an open reading frame predicted to encode a sortase-dependent surface protein with sequence similarity to the O-glycosidase of
Bifidobacterium longum
. Deletion of this pneumococcal open reading frame confirmed that this gene encodes an O-glycosidase. Experiments using a model glycoconjugate demonstrated that this O-glycosidase, together with the neuraminidase NanA, is required for
S. pneumoniae
to cleave sialylated core-1 O-linked glycans. The ability of the O-glycosidase mutant to cleave this glycan structure was restored by both genetic complementation and the addition of O-glycosidase. The mutant showed a reduction in adherence to human airway epithelial cells and a significantly decreased ability to colonize the upper respiratory tract, suggesting that cleavage of core-1 O-linked glycans enhances the ability of
S. pneumoniae
to colonize the human airway.
Details
- Title: Subtitle
- Identification of a Pneumococcal Glycosidase That Modifies O-Linked Glycans
- Creators
- Carolyn Marion - Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's HospitalDominique H Limoli - Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's HospitalGregory S Bobulsky - Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's HospitalJessica L Abraham - Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's HospitalAmanda M Burnaugh - Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's HospitalSamantha J King - Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital
- Resource Type
- Journal article
- Publication Details
- Infection and immunity, Vol.77(4), pp.1389-1396
- DOI
- 10.1128/IAI.01215-08
- PMID
- 19139197
- PMCID
- PMC2663135
- NLM abbreviation
- Infect Immun
- ISSN
- 0019-9567
- eISSN
- 1098-5522
- Publisher
- American Society for Microbiology (ASM)
- Language
- English
- Date published
- 04/2009
- Academic Unit
- Microbiology and Immunology
- Record Identifier
- 9984083884302771
Metrics
14 Record Views