Caulobacter crescentus Adapts to Phosphate Starvation by Synthesizing Anionic Glycoglycerolipids and a Novel Glycosphingolipid.

Loading...
Thumbnail Image

Date

2019-04-02

Authors

Stankeviciute, Gabriele
Guan, Ziqiang
Goldfine, Howard
Klein, Eric A

Journal Title

Journal ISSN

Volume Title

Repository Usage Stats

65
views
22
downloads

Citation Stats

Abstract

Caulobacter crescentus adapts to phosphate starvation by elongating its cell body and a polar stalk structure. The stalk is an extension of the Gram-negative envelope containing inner and outer membranes as well as a peptidoglycan cell wall. Cellular elongation requires a 6- to 7-fold increase in membrane synthesis, yet phosphate limitation would preclude the incorporation of additional phospholipids. In the place of phospholipids, C. crescentus can synthesize several glycolipid species, including a novel glycosphingolipid (GSL-2). While glycosphingolipids are ubiquitous in eukaryotes, the presence of GSL-2 in C. crescentus is surprising since GSLs had previously been found only in Sphingomonas species, in which they play a role in outer membrane integrity. In this paper, we identify three proteins required for GSL-2 synthesis: CcbF catalyzes the first step in ceramide synthesis, while Sgt1 and Sgt2 sequentially glycosylate ceramides to produce GSL-2. Unlike in Sphingomonas, GSLs are nonessential in C. crescentus; however, the presence of ceramides does contribute to phage resistance and susceptibility to the cationic antimicrobial peptide polymyxin B. The identification of a novel lipid species specifically produced upon phosphate starvation suggests that bacteria may be able to synthesize a wider variety of lipids in response to stresses than previously observed. Uncovering these lipids and their functional relevance will provide greater insight into microbial physiology and environmental adaptation.IMPORTANCE Bacteria adapt to environmental changes in a variety of ways, including altering their cell shape. Caulobacter crescentus adapts to phosphate starvation by elongating its cell body and a polar stalk structure containing both inner and outer membranes. While we generally think of cellular membranes being composed largely of phospholipids, cellular elongation occurs when environmental phosphate, and therefore phospholipid synthesis, is limited. In order to adapt to these environmental constraints, C. crescentus synthesizes several glycolipid species, including a novel glycosphingolipid. This finding is significant because glycosphingolipids, while ubiquitous in eukaryotes, are extremely rare in bacteria. In this paper, we identify three proteins required for GSL-2 synthesis and demonstrate that they contribute to phage resistance. These findings suggest that bacteria may synthesize a wider variety of lipids in response to stresses than previously observed.

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1128/mBio.00107-19

Publication Info

Stankeviciute, Gabriele, Ziqiang Guan, Howard Goldfine and Eric A Klein (2019). Caulobacter crescentus Adapts to Phosphate Starvation by Synthesizing Anionic Glycoglycerolipids and a Novel Glycosphingolipid. mBio, 10(2). 10.1128/mBio.00107-19 Retrieved from https://hdl.handle.net/10161/19682.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.

Scholars@Duke

Guan

Ziqiang Guan

Research Professor in Biochemistry

We develop and apply mass spectrometry techniques to address biochemical and biomedical questions that are lipid-related. Research projects include:

1) Structural lipidomics

o   Develop and apply high resolution tandem mass spectrometry-based lipidomics for the discovery, structural elucidation and functional study of novel lipids.

2) Elucidation of novel pathways/enzymes of lipid biosynthesis and metabolism

o   Genetic, biochemical and MS approaches are employed to identify the substrates and pathways involved in lipid biosynthesis and metabolism

3) Identification of lipid biomarkers of genetic diseases and cancers

o    Provide molecular insights into the disease mechanisms, as well as to serve as the diagnostic and prognostic tools of diseases.


Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.