TY  - JOUR
A1  - Fazeli, Gholamreza
A1  - Beer, Katharina B.
A1  - Geisenhof, Michaela
A1  - Tröger, Sarah
A1  - König, Julia
A1  - Müller-Reichert, Thomas
A1  - Wehman, Ann M.
T1  - Loss of the Major Phosphatidylserine or Phosphatidylethanolamine Flippases Differentially Affect Phagocytosis
JF  - Frontiers in Cell and Developmental Biology
N2  - The lipids phosphatidylserine (PtdSer) and phosphatidylethanolamine (PtdEth) are normally asymmetrically localized to the cytosolic face of membrane bilayers, but can both be externalized during diverse biological processes, including cell division, cell fusion, and cell death. Externalized lipids in the plasma membrane are recognized by lipid-binding proteins to regulate the clearance of cell corpses and other cell debris. However, it is unclear whether PtdSer and PtdEth contribute in similar or distinct ways to these processes. We discovered that disruption of the lipid flippases that maintain PtdSer or PtdEth asymmetry in the plasma membrane have opposite effects on phagocytosis in Caenorhabditis elegans embryos. Constitutive PtdSer externalization caused by disruption of the major PtdSer flippase TAT-1 led to increased phagocytosis of cell debris, sometimes leading to two cells engulfing the same debris. In contrast, PtdEth externalization caused by depletion of the major PtdEth flippase TAT-5 or its activator PAD-1 disrupted phagocytosis. These data suggest that PtdSer and PtdEth externalization have opposite effects on phagocytosis. Furthermore, externalizing PtdEth is associated with increased extracellular vesicle release, and we present evidence that the extent of extracellular vesicle accumulation correlates with the extent of phagocytic defects. Thus, a general loss of lipid asymmetry can have opposing impacts through different lipid subtypes simultaneously exerting disparate effects.
KW  - phagocytosis
KW  - lipid asymmetry
KW  - flippase
KW  - phosphatidylserine
KW  - phosphatidylethanolamine
KW  - extracellular vesicle
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208771
SN  - 2296-634X
VL  - 8
ER  - 
TY  - JOUR
A1  - König, Julia
A1  - Guerreiro, Marco Alexandre
A1  - Peršoh, Derek
A1  - Begerow, Dominik
A1  - Krauss, Jochen
T1  - Knowing your neighbourhood - the effects of Epichloë endophytes on foliar fungal assemblages in perennial ryegrass in dependence of season and land-use intensity
JF  - PeerJ
N2  - Epichloë endophytes associated with cool-season grass species can protect their hosts from herbivory and can suppress mycorrhizal colonization of the hosts’ roots. However, little is known about whether or not Epichloë endophyte infection can also change the foliar fungal assemblages of the host. We tested 52 grassland study sites along a land-use intensity gradient in three study regions over two seasons (spring vs. summer) to determine whether Epichloë infection of the host grass Lolium perenne changes the fungal community structure in leaves. Foliar fungal communities were assessed by Next Generation Sequencing of the ITS rRNA gene region. Fungal community structure was strongly affected by study region and season in our study, while land-use intensity and infection with Epichloë endophytes had no significant effects. We conclude that effects on non-systemic endophytes resulting from land use practices and Epichloë infection reported in other studies were masked by local and seasonal variability in this study’s grassland sites.
KW  - endophytic fungi
KW  - symbiosis
KW  - Lolium perenne
KW  - land use
KW  - fungus-plant interaction
KW  - foliar fungal community
KW  - Epichloë
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176814
VL  - 6
IS  - e4660
ER  -