Ornithine Lipids and Other Amino Acid-Containing Acyloxyacyl Lipids

Sohlenkamp, Christian

doi:10.1007/978-3-319-43676-0_13-1

Cited by 3 publications

(2 citation statements)

References 52 publications

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“…The improved tumorigenesis was hypothesized to be due to the recognition of ornithine lipids as a MAMP. Some ornithine lipids or structurally similar molecules are indeed recognized by animal or plant immune systems (Sohlenkamp, 2019). Furthermore, A. tumefaciens and its close relative Rhizobium meliloti possess variants of the flagellin domain flg15 that strongly diverged from those of other bacteria and had no eliciting activity when assayed on tomato (Felix et al, 1999).…”

Section: Detection -Mamp Triggered Immunitymentioning

confidence: 99%

Agrobacterium strains and strain improvement: Present and outlook

Saeger

Park

Chung

et al. 2021

Biotechnology Advances

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Section: Detection -Mamp Triggered Immunitymentioning

confidence: 99%

Agrobacterium strains and strain improvement: Present and outlook

Saeger

Park

Chung

et al. 2021

Biotechnology Advances

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“…It is also a key to the biosynthesis of polyamines, a class of compounds involved in a variety of cellular processes, such as gene expression, cell growth, survival, and stress response ( Gevrekci, 2017 ). Additionally, Orn can be used for the synthesis of phosphorus-free ornithine lipids, which are alternative membrane lipids activated under stress and widespread among eubacteria ( Sohlenkamp and Geiger, 2016 ; Sohlenkamp, 2019 ). Combining these growth phase observations, we can postulate that

is reacting with RSH molecules, and subsequent stress response may be in part dealt with changes in membrane lipids.…”

Section: Discussionmentioning

confidence: 99%

Untargeted Metabolomics Investigation on Selenite Reduction to Elemental Selenium by Bacillus mycoides SeITE01

et al. 2021

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Bacillus mycoides SeITE01 is an environmental isolate that transforms the oxyanion selenite (SeO32−) into the less bioavailable elemental selenium (Se0) forming biogenic selenium nanoparticles (Bio-SeNPs). In the present study, the reduction of sodium selenite (Na2SeO3) by SeITE01 strain and the effect of SeO32− exposure on the bacterial cells was examined through untargeted metabolomics. A time-course approach was used to monitor both cell pellet and cell free spent medium (referred as intracellular and extracellular, respectively) metabolites in SeITE01 cells treated or not with SeO32−. The results show substantial biochemical changes in SeITE01 cells when exposed to SeO32−. The initial uptake of SeO32− by SeITE01 cells (3h after inoculation) shows both an increase in intracellular levels of 4-hydroxybenzoate and indole-3-acetic acid, and an extracellular accumulation of guanosine, which are metabolites involved in general stress response adapting strategies. Proactive and defensive mechanisms against SeO32− are observed between the end of lag (12h) and beginning of exponential (18h) phases. Glutathione and N-acetyl-L-cysteine are thiol compounds that would be mainly involved in Painter-type reaction for the reduction and detoxification of SeO32− to Se0. In these growth stages, thiol metabolites perform a dual role, both acting against the toxic and harmful presence of the oxyanion and as substrate or reducing sources to scavenge ROS production. Moreover, detection of the amino acids L-threonine and ornithine suggests changes in membrane lipids. Starting from stationary phase (24 and 48h), metabolites related to the formation and release of SeNPs in the extracellular environment begin to be observed. 5-hydroxyindole acetate, D-[+]-glucosamine, 4-methyl-2-oxo pentanoic acid, and ethanolamine phosphate may represent signaling strategies following SeNPs release from the cytoplasmic compartment, with consequent damage to SeITE01 cell membranes. This is also accompanied by intracellular accumulation of trans-4-hydroxyproline and L-proline, which likely represent osmoprotectant activity. The identification of these metabolites suggests the activation of signaling strategies that would protect the bacterial cells from SeO32− toxicity while it is converting into SeNPs.

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Impact of Phosphate Availability on Membrane Lipid Content of the Model Strains, Streptomyces lividans and Streptomyces coelicolor

et al. 2021

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In this issue we demonstrated that the phospholipid content of Streptomyces lividans varies greatly with Pi availability being was much lower in Pi limitation than in Pi proficiency whereas that of Streptomyces coelicolor varied little with Pi availability. In contrast the content in phosphate free ornithine lipids was enhanced in both strains in condition of phosphate limitation. Ornithine lipids biosynthesis starts with the N-acylation of ornithine to form lyso-ornithine that is then O-acylated to yield ornithine lipid. The operon sco1222-23 was proposed to be involved in the conversion of specific amino acids into ornithine in condition of phosphate limitation whereas the sco0921-20 operon encoding N- and O-acyltransferase, respectively, was shown to be involved in the biosynthesis of these lipids. The expression of these two operons was shown to be under the positive control of the two components system PhoR/PhoP and thus induced in phosphate limitation. The expression of phoR/phoP being weak in S. coelicolor, the poor expression of these operons resulted into a fivefold lower ornithine lipids content in this strain compared to S. lividans. In the deletion mutant of the sco0921-20 operon of S. lividans, lyso-ornithine and ornithine lipids were barely detectable and TAG content was enhanced. The complementation of this mutant by the sco0921-20 operon or by sco0920 alone restored ornithine lipids and TAG content to wild type level and was correlated with a twofold increase in the cardiolipin content. This suggested that SCO0920 bears, besides its broad O-acyltransferase activity, an N-acyltransferase activity and this was confirmed by the detection of lyso-ornithine in this strain. In contrast, the complementation of the mutant by sco0921 alone had no impact on ornithine lipids, TAG nor cardiolipin content but was correlated with a high lyso-ornithine content. This confirmed that SCO0921 is a strict N-acyltransferase. However, interestingly, the over-expression of the sco0921-20 operon or of sco0921 alone in S. coelicolor, led to an almost total disappearance of phosphatidylinositol that was correlated with an enhanced DAG and TAG content. This suggested that SCO0921 also acts as a phospholipase C, degrading phosphatidylinositol to indirectly supply of phosphate in condition of phosphate limitation.

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Ornithine Lipids and Other Amino Acid-Containing Acyloxyacyl Lipids

Cited by 3 publications

References 52 publications

Agrobacterium strains and strain improvement: Present and outlook

Agrobacterium strains and strain improvement: Present and outlook

Untargeted Metabolomics Investigation on Selenite Reduction to Elemental Selenium by Bacillus mycoides SeITE01

Impact of Phosphate Availability on Membrane Lipid Content of the Model Strains, Streptomyces lividans and Streptomyces coelicolor

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