presentation by jennifer unterbrink pcdu seminar november 11th, 2015
TRANSCRIPT
presentation by Jennifer UnterbrinkPCDU seminar
November 11th, 2015
ESCRT Complex and Retromer
Endosomes in plants
Endosomes in plants
www.illuminatedcell.com
Endosomes in plants heterogenous collection of organelles
function:
sorting and delivery from the cell surface
transport from TGN to lysosome/ vacuole
biosynthetic AND endocytotic pathway
Multivesicular bodies
Winter and Hauser, 2006. Trends in Plant Sc. Vol.11 No.3
Endosomal trafficking
retrograde transportanterograde transport
biosynthetical/ secretory transportBruce Alberts (Ed.), Molecular biology of the cell
ER
Golgi
EE
secretory vesicles
PM
LE
V/ L
Coats of the late endosomal system
Retromer schematic
Schellmann and Pimpl, 2009: Curr. Opinion in Plant Biol. 12
SNX: phox-homology domain, allows association with phospholipids (PI3P)
BAR domain
Bin-Amphiphysin-Rvs
Retromer structure
SNXs important for Retromer function
Rojas et al., 2007. Mol. and Cell. Biol. 02/2007
Plant Retromer
Schellmann and Pimpl, 2009: Curr. Opinion in Plant Biol. 12
ESCRTs
ESCRT subunits in plants
Schellmann and Pimpl, 2009: Curr. Opinion in Plant Biol. 12
ESCRT subunits in plants
Schellmann and Pimpl, 2009: Curr. Opinion in Plant Biol. 12
ESCRTs in cytokinesis
Spitzer et al., 2006. Development 133
The coat to perdition
www.nature.com, 2015/11/08
ESCRT-dependent protein sorting
Winter and Hauser, 2006. Trends in Plant Sc. 11
Ubiquitin
www.nobelprize.org/nobel_prizes/chemistry/laureates/2004/chempub1high.jpg
ESCRT-dependent vesicle formation
Cai et al., 2014. Plant Physiol. Vol.165 No.3c
Figure 7.Immunogold detection of VSRs in wild-type and transgenic Arabidopsis plants with induced expression of ESCRT-III mutants. Six-day-old wild-type plants (A and B) and transgenic plants (C–J) germinated and cultured in the absence of inducers were transferred onto medium containing 10 μM β-estradiol for 24 h to induce the expression of VPS20.1-1-112-YFP (C and D), SNF7.1(L22W)-YFP (E and F), VPS24.1-1-152-YFP (G and H), or VPS2.1-1-179-YFP (I and J). Arabidopsis roots were subjected to high-pressure frozen/freeze substitution followed by ultrathin sectioning and immunogold labeling using VSR antibodies. Bar = 100 nm.
FREE1
peripheral membrane-associated protein
Gao et al., 2014. Curr. Biol. 24
binds to PI3P via the FYVE domain
FYVE domainFYVE zinc finger domainnamed after the Cys-rich proteins Fab1, YOTB, Vac1, EEA1
binds PI3P
is composed of two small β-hairpins (zinc knuckles)followed by a α-helix
FYVE finger binds to two Zn-ions
FREE1 function
transposon insertion in A.thaliana
Gao et al., 2014. Curr. Biol. 24
homozygous free1 mutants are not viable
expression of GFP-tagged FREE1 rescued the seedling lethality
FREE1 function
Gao et al., 2014. Curr. Biol. 24
https://www.youtube.com/watch?v=_4DM48ZPR0A