Intracellular Transport Pathways

Three major coats function in the secretory pathway

Intracellular Transport Pathways AP2 AP1, 3

Composition of the COPII coat

Structure of Sec13/31 cage Stagg et al. Nature 2006

COPI coat assembly

COPI-coated vesicles

Clathrin-coated vesicles

Clathrin-coated vesicles

Clathrin-coated vesicles

Endocytosis requires dynamin GTPase

Dynamin forms a neck

- Priming: Recruitment of GTP-binding protein GEF localization! - Coat recruitment - Cargo recruitment interactions with coat components fusion machinery components

SNARE Hypothesis v- and t-SNAREs are part of the fusion machinery v- and t-SNAREs provide compartment specificity

“SNAREpin model

HA-induced membrane fusion

SNARE-mediated fusion

SNARE-mediated fusion

v/t SNARE fusion cycle

v/t SNAREs are compartment-specific From McNew et al. (2000)

v/t SNAREs are compartment-specific From Parlati et al. (2000)

compartment-specific v/t SNAREs are compartment-specific From Parlati et al. (2000)

v/t SNAREs are compartment-specific Parlati et al. (2000)

Flipped SNAREs can fuse cells Hu et al., Science 2003