The Caenorhabditis elegans bus-2 mutant reveals a new class of O-glycans affecting bacterial resistance.
Microbacterium nematophilum causes a deleterious infection of the C. elegans hindgut initiated by adhesion to rectal and anal cuticle. C. elegans bus-2 mutants, which are resistant to M. nematophilum and also to the formation of surface biofilms by Yersinia sp., carry genetic lesions in a putative glycosyltransferase containing conserved domains of core-1 beta1,3-galactosyltransferases. bus-2 is predicted to act in the synthesis of core-1 type O-glycans. This observation implies that the infection requires the presence of host core-1 O-glycoconjugates and is therefore carbohydrate-dependent. Chemical analysis reported here reveals that bus-2 is indeed deficient in core-1 O-glycans. These mutants also exhibit a new subclass of O-glycans whose structures were determined by high performance tandem mass spectrometry; these are highly fucosylated and have a novel core that contains internally linked GlcA. Lectin studies showed that core-1 glycans and this novel class of O-glycans are both expressed in the tissue that is infected in the wild type worms. In worms having the bus-2 genetic background, core-1 glycans are decreased, whereas the novel fucosyl O-glycans are increased in abundance in this region. Expression analysis using a red fluorescent protein marker showed that bus-2 is expressed in the posterior gut, cuticle seam cells, and spermatheca, the first two of which are likely to be involved in secreting the carbohydrate-rich surface coat of the cuticle. Therefore, in the bus-2 background of reduced core-1 O-glycans, the novel fucosyl glycans likely replace or mask remaining core-1 ligands, leading to the resistance phenotype. There are more than 35 Microbacterium species, some of which are pathogenic in man. This study is the first to analyze the biochemistry of adhesion to a host tissue by a Microbacterium species.
Palaima
Elizabeth
E
Department of Biochemistry and Molecular Medicine, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
Leymarie
Nancy
N
Stroud
Dave
D
Mizanur
Rahman M
RM
Hodgkin
Jonathan
J
Gravato-Nobre
Maria J
MJ
Costello
Catherine E
CE
Cipollo
John F
JF
D000818:Animals; D001422:Bacterial Adhesion; D018441:Biofilms; D017173:Caenorhabditis elegans; D002241:Carbohydrates / Q000737:chemistry; D024881:Drug Resistance, Bacterial; D006023:Glycoproteins / Q000737:chemistry; D008024:Ligands; D008164:Luminescent Proteins / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D009154:Mutation; D009844:Oligosaccharides / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry / Q000235:genetics*; D053719:Tandem Mass Spectrometry / Q000379:methods; D000097573:Red Fluorescent Protein
D002241:Carbohydrates; D006023:Glycoproteins; D008024:Ligands; D008164:Luminescent Proteins; D009844:Oligosaccharides; D011134:Polysaccharides; D000097573:Red Fluorescent Protein
Genetics. 2007 Feb;175(2):681-97
17151260
Curr Biol. 2004 Jun 22;14(12):1105-11
15203005
Science. 2001 Aug 3;293(5531):860-4
11486087
Histochemistry. 1994 Jun;101(5):379-84
7523338
J Am Soc Mass Spectrom. 2007 Oct;18(10):1799-812
17719235
Dev Growth Differ. 2000 Feb;42(1):69-77
10831045
Biotechniques. 2002 Apr;32(4):728-30
11962590
J Biol Chem. 2004 Dec 17;279(51):52893-903
15452127
Nat Genet. 2001 Mar;27(3):332-6
11242119
Prog Nucleic Acid Res Mol Biol. 1998;60:1-27
9594569
Nature. 2002 May 16;417(6886):243-4
12015591
Biochimie. 2001 Jul;83(7):565-73
11522384
Biochimie. 2001 Aug;83(8):713-8
11530202
J Am Chem Soc. 2003 Dec 31;125(52):16213-9
14692762
Nat Med. 2003 May;9(5):548-53
12692541
J Clin Microbiol. 2008 Nov;46(11):3646-52
18799696
Nucleic Acids Res. 2004 Jul 1;32(Web Server issue):W327-31
15215404
Cell Microbiol. 2001 Jun;3(6):381-93
11422081
Genetics. 2005 Nov;171(3):1033-45
16079230
Curr Biol. 2000 Dec 14-28;10(24):1615-8
11137017
J Biol Chem. 2007 Feb 2;282(5):3302-11
17135259
Genetics. 1974 May;77(1):71-94
4366476
Genetics. 1992 Aug;131(4):867-81
1516818
J Biol Chem. 2004 Jul 16;279(29):30440-8
15123614
Genetics. 2007 May;176(1):221-30
17339204
Biochem J. 2001 Jul 1;357(Pt 1):167-82
11415447
Dev Biol. 2008 May 15;317(2):549-59
18395708
Protein Sci. 2003 Jul;12(7):1418-31
12824488
Curr Biol. 2004 Jul 27;14(14):1256-61
15268855
J Biol Chem. 2003 Nov 14;278(46):45594-602
12944392
PLoS Pathog. 2008 Jan;4(1):e2
18179282
Eur J Biochem. 1988 Apr 5;173(1):9-16
2833395
Biochem J. 1975 Dec;151(3):491-5
1218089
Trends Microbiol. 2005 Mar;13(3):119-27
15737730
Science. 1993 Dec 17;262(5141):1892-5
8018146