Limits...
Flagellar membranes are rich in raft-forming phospholipids.

Serricchio M, Schmid AW, Steinmann ME, Sigel E, Rauch M, Julkowska D, Bonnefoy S, Fort C, Bastin P, Bütikofer P - Biol Open (2015)

Bottom Line: Our analyses revealed that phosphatidylethanolamine, phosphatidylserine, ceramide and the sphingolipids inositol phosphorylceramide and sphingomyelin are enriched in flagella relative to whole cells.Within individual glycerophospholipid classes, we observed a preference for ether-type over diacyl-type molecular species in membranes of flagella.Our study provides direct evidence for a preferential presence of raft-forming phospholipids in flagellar membranes of T. brucei.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biochemistry & Molecular Medicine, University of Bern, Bern 3012, Switzerland peter.buetikofer@ibmm.unibe.ch mauro.serricchio@utoronto.ca.

No MeSH data available.


Comparison of chromatograms of the most intense molecular species of different phospholipid classes acquired in negative ionisation mode. Total ion chromatograms and retention times of the three most intense species of PE, PC, SM, IPC and PI of lipid extracts from whole cells (A) or isolated flagella (B).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4582118&req=5

BIO011957F5: Comparison of chromatograms of the most intense molecular species of different phospholipid classes acquired in negative ionisation mode. Total ion chromatograms and retention times of the three most intense species of PE, PC, SM, IPC and PI of lipid extracts from whole cells (A) or isolated flagella (B).

Mentions: To determine depletion or enrichment of a phospholipid class in flagella relative to whole cells, the sums of the signal intensities of all molecular species of a given class were compared. To correct for intensity differences due to varying amounts of injected material between different runs, signal intensities of all identified phospholipids were summarized and normalized to match the corresponding reference sample. To visualize the relative changes between individual phospholipid classes, elution profiles of the three most intense species of PE, PC, SM, IPC and PI from whole cell extracts and flagella are depicted in Fig. 5. The comparison shows that PE, SM and IPC are highly enriched relative to PC and PI in flagella (Fig. 5B) compared to whole cells (Fig. 5A). Comparisons of the normalized signal intensities of all phospholipid classes (plus ceramide) between flagella and whole cells show that, independent of the ionisation mode used, PC, PI and PG were depleted in flagella by at least 45% (Fig. 6A,B), whereas PE, SM, PS, IPC and ceramide were enriched by 150–320% in flagella compared to whole cells (Fig. 6A,B). Analysis of molecular species within a given lipid class showed that nearly all species of PC, PI, SM, IPC, PG and ceramide behaved similarly, meaning that they were either enriched or depleted in flagella relative to whole cells (Fig. 6C,D). In contrast, among PE and PS molecular species some showed enrichment in flagella while others were depleted (Fig. 6C,D). Remarkably, we found that most ether-type PC molecular species were enriched in flagella relative to whole cells. The relative amounts of ether-type PC molecular species increased from 24.9±0.01% (analysis in negative mode) and 30.3±2.8% (analysis in positive mode) in whole cells to 37.5±2.2% and 44.9±2.9% in flagella, respectively (Table 1). A similar enrichment of ether-type molecular species in flagella versus whole cells was also observed for PS and PE (Table 1). Together these results demonstrate that ether-type phospholipid molecular species are clearly enriched in flagella compared to whole cells and that this relative change can be detected in both negative and positive mode of LC-MS/MS analysis.Fig. 5.


Flagellar membranes are rich in raft-forming phospholipids.

Serricchio M, Schmid AW, Steinmann ME, Sigel E, Rauch M, Julkowska D, Bonnefoy S, Fort C, Bastin P, Bütikofer P - Biol Open (2015)

Comparison of chromatograms of the most intense molecular species of different phospholipid classes acquired in negative ionisation mode. Total ion chromatograms and retention times of the three most intense species of PE, PC, SM, IPC and PI of lipid extracts from whole cells (A) or isolated flagella (B).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4582118&req=5

BIO011957F5: Comparison of chromatograms of the most intense molecular species of different phospholipid classes acquired in negative ionisation mode. Total ion chromatograms and retention times of the three most intense species of PE, PC, SM, IPC and PI of lipid extracts from whole cells (A) or isolated flagella (B).
Mentions: To determine depletion or enrichment of a phospholipid class in flagella relative to whole cells, the sums of the signal intensities of all molecular species of a given class were compared. To correct for intensity differences due to varying amounts of injected material between different runs, signal intensities of all identified phospholipids were summarized and normalized to match the corresponding reference sample. To visualize the relative changes between individual phospholipid classes, elution profiles of the three most intense species of PE, PC, SM, IPC and PI from whole cell extracts and flagella are depicted in Fig. 5. The comparison shows that PE, SM and IPC are highly enriched relative to PC and PI in flagella (Fig. 5B) compared to whole cells (Fig. 5A). Comparisons of the normalized signal intensities of all phospholipid classes (plus ceramide) between flagella and whole cells show that, independent of the ionisation mode used, PC, PI and PG were depleted in flagella by at least 45% (Fig. 6A,B), whereas PE, SM, PS, IPC and ceramide were enriched by 150–320% in flagella compared to whole cells (Fig. 6A,B). Analysis of molecular species within a given lipid class showed that nearly all species of PC, PI, SM, IPC, PG and ceramide behaved similarly, meaning that they were either enriched or depleted in flagella relative to whole cells (Fig. 6C,D). In contrast, among PE and PS molecular species some showed enrichment in flagella while others were depleted (Fig. 6C,D). Remarkably, we found that most ether-type PC molecular species were enriched in flagella relative to whole cells. The relative amounts of ether-type PC molecular species increased from 24.9±0.01% (analysis in negative mode) and 30.3±2.8% (analysis in positive mode) in whole cells to 37.5±2.2% and 44.9±2.9% in flagella, respectively (Table 1). A similar enrichment of ether-type molecular species in flagella versus whole cells was also observed for PS and PE (Table 1). Together these results demonstrate that ether-type phospholipid molecular species are clearly enriched in flagella compared to whole cells and that this relative change can be detected in both negative and positive mode of LC-MS/MS analysis.Fig. 5.

Bottom Line: Our analyses revealed that phosphatidylethanolamine, phosphatidylserine, ceramide and the sphingolipids inositol phosphorylceramide and sphingomyelin are enriched in flagella relative to whole cells.Within individual glycerophospholipid classes, we observed a preference for ether-type over diacyl-type molecular species in membranes of flagella.Our study provides direct evidence for a preferential presence of raft-forming phospholipids in flagellar membranes of T. brucei.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biochemistry & Molecular Medicine, University of Bern, Bern 3012, Switzerland peter.buetikofer@ibmm.unibe.ch mauro.serricchio@utoronto.ca.

No MeSH data available.