Alibaud, L and Alahari, A and Trivelli, X and Ojha, AK and Hatfull, GF and Guerardel, Y and Kremer, L
(2010)
Temperature-dependent regulation of mycolic acid cyclopropanation in saprophytic mycobacteria: Role of the Mycobacterium smegmatis 1351 gene (MSMEG-1351) in cis-cyclopropanation of α-mycolates.
Journal of Biological Chemistry, 285 (28).
21698 - 21707.
ISSN 0021-9258
Abstract
The cell envelope is a crucial determinant of virulence and drug resistance in Mycobacterium tuberculosis. Several features of pathogenesis and immunomodulation of host responses are attributable to the structural diversity in cell wall lipids, particularly in the mycolic acids. Structural modification of the α-mycolic acid by introduction of cyclopropane rings as catalyzed by the methyltransferase, PcaA, is essential for a lethal, persistent infection and the cording phenotype in M. tuberculosis. Here, we demonstrate the presence of cyclopropanated cell wall mycolates in the nonpathogenic strain Mycobacterium smegmatis and identify MSMEG-1351 as a gene encoding a PcaA homologue. Interestingly, α-mycolic acid cyclopropanation was inducible in cultures grown at 25 °C. The growth temperature modulation of the cyclopropanating activity was determined by high resolution magic angle spinning NMR analyses on whole cells. In parallel, quantitative reverse transcription-PCR analysis showed that MSMEG-1351 gene expression is up-regulated at 25 °C compared with 37 °C. An MSMEG-1351 knock-out strain of M. smegmatis, generated by recombineering, exhibited a deficiency in cyclopropanation of α-mycolates. The functional equivalence of PcaA and MSMEG-1351 was established by cross-complementation in the MSMEG-1351 knock-out mutant and also in a ΔpcaA strain of Mycobacterium bovis BCG. Overexpression of MSMEG-1351 restored the wild-type mycolic acid profile and the cording phenotype in BCG. Although the biological significance of mycolic acid cyclopropanation in nonpathogenic mycobacteria remains unclear, it likely represents a mechanism of adaptation of cell wall structure and composition to cope with environmental factors. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.
Share
| Citation/Export: |
|
| Social Networking: |
|
Details
| Item Type: |
Article
|
| Status: |
Published |
| Creators/Authors: |
| Creators | Email | Pitt Username | ORCID  |
|---|
| Alibaud, L | | | | | Alahari, A | | | | | Trivelli, X | | | | | Ojha, AK | | | | | Hatfull, GF | gfh@pitt.edu | GFH | | | Guerardel, Y | | | | | Kremer, L | | | |
|
| Date: |
9 July 2010 |
| Date Type: |
Publication |
| Journal or Publication Title: |
Journal of Biological Chemistry |
| Volume: |
285 |
| Number: |
28 |
| Page Range: |
21698 - 21707 |
| DOI or Unique Handle: |
10.1074/jbc.m110.125724 |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Biological Sciences |
| Refereed: |
Yes |
| ISSN: |
0021-9258 |
| Related URLs: |
|
| MeSH Headings: |
Cyclopropanes--chemistry; Fatty Acids--metabolism; Gene Expression Regulation, Bacterial; Genetic Complementation Test; Lipids--chemistry; Magnetic Resonance Spectroscopy; Mass Spectrometry--methods; Methyltransferases--metabolism; Mycobacterium bovis--metabolism; Mycobacterium smegmatis--metabolism; Mycolic Acids--chemistry; Mycolic Acids--metabolism; Phenotype; Reverse Transcriptase Polymerase Chain Reaction; Temperature; Up-Regulation |
| Other ID: |
NLM PMC2898377 |
| PubMed Central ID: |
PMC2898377 |
| PubMed ID: |
20457615 |
| Date Deposited: |
29 Oct 2012 21:19 |
| Last Modified: |
28 Sep 2022 13:24 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/16114 |
Metrics
Monthly Views for the past 3 years
Plum Analytics
Altmetric.com
Actions (login required)
 |
View Item |
![[img]](https://d-scholarship.pitt.edu/style/images/fileicons/text_plain.png)
![[feed]](/images/feed-icon-32x32.png){kind=icon}