Dissecting the secretory pathway with electrophoresis reveals intra-Golgi trafficking pathways and enables compilation of sub-Golgi and sub-ER proteomes.

ABSTRACT: The Golgi is the hub of the eukaryotic secretory pathway, trafficking proteins and lipids, as well as synthesizing complex sugars. Different biosynthetic reactions are associated with different compartments of its complex architecture. Although pre- and post-Golgi trafficking has been much studied, comparatively little is known about intra-Golgi organization. In this study, secretory vesicles and organelles were separated along an electrophoretic gradient at sub-Golgi resolution, presenting snapshots of the changing relative abundance of hundreds of resident and cargo proteins and glycans in transit through the ER, Golgi compartments and post-Golgi compartments. Furthermore, grouped features in migration profiles reveal the dominant intra-Golgi protein trafficking pathways, showing separate routes for cargo and different groups of resident proteins. As few structural characteristics of proteins or sequence motifs have been associated with specific regions of the Golgi stack, we also carried out a comparative analysis of the transmembrane regions of resident proteins associated with the main migratory profiles identifying the presence of charge amino acids adjacent to the transmembrane helix, exoplasmic Ser and Thr content and helix composition as likely contributors to protein sorting mechanisms.

INSTRUMENT(S): TripleTOF 5600, Q Exactive

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Plant Cell, Cell Suspension Culture

SUBMITTER: Harriet Parsons  

LAB HEAD: Kathryn s. Lilley

PROVIDER: PXD004596 | Pride | 2019-09-11

REPOSITORIES: Pride