Expression of sialic acids and other nonulosonic acids in <it>Leptospira</it>
<p>Abstract</p> <p>Background</p> <p>Sialic acids are negatively charged nine carbon backbone sugars expressed on mammalian cell surfaces. Sialic acids are part of a larger family of nonulosonic acid (NulO) molecules that includes pseudaminic and legionaminic acids. Mic...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2012-08-01
|
| Series: | BMC Microbiology |
| Subjects: | |
| Online Access: | http://www.biomedcentral.com/1471-2180/12/161 |
| _version_ | 1818835745424539648 |
|---|---|
| author | Ricaldi N Jessica Matthias Michael A Vinetz Joseph M Lewis Amanda L |
| author_facet | Ricaldi N Jessica Matthias Michael A Vinetz Joseph M Lewis Amanda L |
| author_sort | Ricaldi N Jessica |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Sialic acids are negatively charged nine carbon backbone sugars expressed on mammalian cell surfaces. Sialic acids are part of a larger family of nonulosonic acid (NulO) molecules that includes pseudaminic and legionaminic acids. Microbial expression of sialic acids and other nonulosonic acids has been shown to contribute to host-microbe interactions in a variety of contexts, including participation in colonization, immune subversion, and behaviors such as biofilm formation, autoagglutination and motility. Previous research has suggested that some spirochetes may also express these molecules.</p> <p>Results</p> <p>Here we use a combination of molecular tools to investigate the presence of NulO biosynthetic gene clusters among clinical and saprophytic isolates of the genus <it>Leptospira</it>. Polymerase chain reaction and Southern blotting suggested that a variety of leptospires encoded NulO biosynthetic pathways. High performance liquid chromatography and mass spectrometry analyses provided biochemical evidence that di-N-acetylated NulO molecules are expressed at relatively high levels by <it>L. interrogans</it> serovar Lai strain 55601, and at lower levels by <it>L. alexanderi</it> serovar Manhao and <it>L. fainei</it> serovar Hurstbridge. Endogenous expression of N-acetylneuraminic acid (Neu5Ac, the most common sialic acid) was documented in <it>L. interrogans</it> serovar Copenhageni strain L1-130. Neu5Ac biosynthesis is also supported by a unique gene fusion event resulting in an enzyme with an N-terminal N-acetylneuraminic acid synthase domain and a C-terminal phosphatase domain. This gene fusion suggests that <it>L. interrogans</it> uses a Neu5Ac biosynthetic pathway more similar to animals than to other bacteria. Analysis of the composition and phylogeny of putative NulO biosynthetic gene clusters in <it>L. interrogans</it> serovar Lai and serovar Copenhageni revealed that both strains have complete biosynthetic pathways for legionamimic acid synthesis, a molecule with the same stereochemistry as sialic acid. Lectin-based affinity purification of NulO-modified molecules, followed by mass spectrometric identification suggests post-translational modification of surface lipoproteins, including Loa22.</p> <p>Conclusions</p> <p><it>Leptospira</it> species encode NulO biosynthetic pathways and synthesize multiple NulO molecules including sialic acid. Additional studies are needed to clarify the exact context and functional significance of NulO expression. These findings have implications for immune evasion during systemic leptospirosis.</p> |
| first_indexed | 2024-12-19T02:55:36Z |
| format | Article |
| id | doaj.art-99ba719ae32f4ce5ad11f9b5748d57f4 |
| institution | Directory Open Access Journal |
| issn | 1471-2180 |
| language | English |
| last_indexed | 2024-12-19T02:55:36Z |
| publishDate | 2012-08-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Microbiology |
| spelling | doaj.art-99ba719ae32f4ce5ad11f9b5748d57f42022-12-21T20:38:21ZengBMCBMC Microbiology1471-21802012-08-0112116110.1186/1471-2180-12-161Expression of sialic acids and other nonulosonic acids in <it>Leptospira</it>Ricaldi N JessicaMatthias Michael AVinetz Joseph MLewis Amanda L<p>Abstract</p> <p>Background</p> <p>Sialic acids are negatively charged nine carbon backbone sugars expressed on mammalian cell surfaces. Sialic acids are part of a larger family of nonulosonic acid (NulO) molecules that includes pseudaminic and legionaminic acids. Microbial expression of sialic acids and other nonulosonic acids has been shown to contribute to host-microbe interactions in a variety of contexts, including participation in colonization, immune subversion, and behaviors such as biofilm formation, autoagglutination and motility. Previous research has suggested that some spirochetes may also express these molecules.</p> <p>Results</p> <p>Here we use a combination of molecular tools to investigate the presence of NulO biosynthetic gene clusters among clinical and saprophytic isolates of the genus <it>Leptospira</it>. Polymerase chain reaction and Southern blotting suggested that a variety of leptospires encoded NulO biosynthetic pathways. High performance liquid chromatography and mass spectrometry analyses provided biochemical evidence that di-N-acetylated NulO molecules are expressed at relatively high levels by <it>L. interrogans</it> serovar Lai strain 55601, and at lower levels by <it>L. alexanderi</it> serovar Manhao and <it>L. fainei</it> serovar Hurstbridge. Endogenous expression of N-acetylneuraminic acid (Neu5Ac, the most common sialic acid) was documented in <it>L. interrogans</it> serovar Copenhageni strain L1-130. Neu5Ac biosynthesis is also supported by a unique gene fusion event resulting in an enzyme with an N-terminal N-acetylneuraminic acid synthase domain and a C-terminal phosphatase domain. This gene fusion suggests that <it>L. interrogans</it> uses a Neu5Ac biosynthetic pathway more similar to animals than to other bacteria. Analysis of the composition and phylogeny of putative NulO biosynthetic gene clusters in <it>L. interrogans</it> serovar Lai and serovar Copenhageni revealed that both strains have complete biosynthetic pathways for legionamimic acid synthesis, a molecule with the same stereochemistry as sialic acid. Lectin-based affinity purification of NulO-modified molecules, followed by mass spectrometric identification suggests post-translational modification of surface lipoproteins, including Loa22.</p> <p>Conclusions</p> <p><it>Leptospira</it> species encode NulO biosynthetic pathways and synthesize multiple NulO molecules including sialic acid. Additional studies are needed to clarify the exact context and functional significance of NulO expression. These findings have implications for immune evasion during systemic leptospirosis.</p>http://www.biomedcentral.com/1471-2180/12/161Sialic acidNonulosonic acid<it>Leptospira</it> |
| spellingShingle | Ricaldi N Jessica Matthias Michael A Vinetz Joseph M Lewis Amanda L Expression of sialic acids and other nonulosonic acids in <it>Leptospira</it> BMC Microbiology Sialic acid Nonulosonic acid <it>Leptospira</it> |
| title | Expression of sialic acids and other nonulosonic acids in <it>Leptospira</it> |
| title_full | Expression of sialic acids and other nonulosonic acids in <it>Leptospira</it> |
| title_fullStr | Expression of sialic acids and other nonulosonic acids in <it>Leptospira</it> |
| title_full_unstemmed | Expression of sialic acids and other nonulosonic acids in <it>Leptospira</it> |
| title_short | Expression of sialic acids and other nonulosonic acids in <it>Leptospira</it> |
| title_sort | expression of sialic acids and other nonulosonic acids in it leptospira it |
| topic | Sialic acid Nonulosonic acid <it>Leptospira</it> |
| url | http://www.biomedcentral.com/1471-2180/12/161 |
| work_keys_str_mv | AT ricaldinjessica expressionofsialicacidsandothernonulosonicacidsinitleptospirait AT matthiasmichaela expressionofsialicacidsandothernonulosonicacidsinitleptospirait AT vinetzjosephm expressionofsialicacidsandothernonulosonicacidsinitleptospirait AT lewisamandal expressionofsialicacidsandothernonulosonicacidsinitleptospirait |