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The activity-dependent bulk endocytosis proteome reveals a key presynaptic role for Rab11

ABSTRACT: Activity-dependent bulk endocytosis (ADBE) is the dominant mode of synaptic vesicle (SV) endocytosis during high frequency stimulation, suggesting it should play key roles in neurotransmission during periods of intense neuronal activity. However efforts in elucidating the physiological role of ADBE have been hampered by the lack of identified molecules which are unique to this endocytosis mode. To address this, we performed proteomic analysis on purified bulk endosomes, which are a key intermediate in ADBE. Bulk endosomes were enriched via two independent approaches, a classical subcellular fractionation method and isolation via magnetic nanoparticles. There was a 79 % overlap in proteins identified via the two protocols and these molecules formed the ADBE proteome. Bioinformatic analysis revealed a strong enrichment in cell adhesion, cytoskeletal and signalling molecules, in addition to expected SV and trafficking proteins. Network analysis identified rab GTPases as a central hub within the ADBE proteome. Subsequent investigation of a subset of these rabs revealed that constitutively active rab11 both facilitated ADBE and accelerated clathrin-mediated endocytosis. This first result suggests that the ADBE proteome will provide a rich resource for the future study of presynaptic function.

INSTRUMENT(S): Orbitrap Fusion ETD

ORGANISM(S): Rattus Norvegicus (rat)

SUBMITTER: Matthias Trost

LAB HEAD: Matthias Trost

PROVIDER: PXD009745 | Pride | 2018-10-15

REPOSITORIES: Pride

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The activity-dependent bulk endocytosis proteome reveals a key presynaptic role for Rab11

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