6533b856fe1ef96bd12b3280

RESEARCH PRODUCT

RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy

Anne FeldmannChristian BehlFazilet BekbulatJennifer JungAndreas KernIvan DikicAlbrecht M. ClementVerena SchmittBernd MoosmannIngrid Koziollek-drechslerNatalie SpangChristian BehrendsChristof HiebelHeike Huesmann

subject

GTPase-activating proteinlipid dropletsrab3 GTP-Binding ProteinsATG16L1DMSO dimethyl sulfoxideFEZ20302 clinical medicineATG autophagy-relatedPhagosomesDAPI 4’ 6-diamidino-2-phenylindoleSQSTM1 sequestosome 1ATG16L1MAP1LC3 microtubule-associated protein 1 light chain 3GFP green fluorescent protein0303 health sciencesGABARAP GABA(A) receptor-associated proteinGTPase-Activating ProteinsCell biologyRAB3GAP1RAB3GAP2RABGAP RAB GTPase activating proteinATG3autophagyCALCOCO2 calcium binding and coiled-coil domain 2Basic Research PaperseV empty vectorATG8ATG5PBS phosphate-buffered salineBiologyPE phosphatidylethanolamineTBC domain TRE2-BUB2-CDC16 domainBAG3GEF guanine nucleotide exchange factor03 medical and health sciencesC. elegans Caenorhabditis elegansAnimalsHumansCaenorhabditis elegansMolecular Biology030304 developmental biologySirolimusDPH 1 6-diphenyl-1 3 5-hexatrieneproteostasisAutophagyBiological TransportCell BiologyFEZ1Bafi bafilomycin A1FEZ fasciculation and elongation protein zetaNBR1 neighbor of BRCA1 gene 1ProteostasissiRNA small interfering RNABSA bovine serum albuminRabLysosomes030217 neurology & neurosurgery

description

Macroautophagy is a degradative pathway that sequesters and transports cytosolic cargo in autophagosomes to lysosomes, and its deterioration affects intracellular proteostasis. Membrane dynamics accompanying autophagy are mostly elusive and depend on trafficking processes. RAB GTPase activating proteins (RABGAPs) are important factors for the coordination of cellular vesicle transport systems, and several TBC (TRE2-BUB2-CDC16) domain-containing RABGAPs are associated with autophagy. Employing C. elegans and human primary fibroblasts, we show that RAB3GAP1 and RAB3GAP2, which are components of the TBC domain-free RAB3GAP complex, influence protein aggregation and affect autophagy at basal and rapamycin-induced conditions. Correlating the activity of RAB3GAP1/2 with ATG3 and ATG16L1 and analyzing ATG5 punctate structures, we illustrate that the RAB3GAPs modulate autophagosomal biogenesis. Significant levels of RAB3GAP1/2 colocalize with members of the Atg8 family at lipid droplets, and their autophagy modulatory activity depends on the GTPase-activating activity of RAB3GAP1 but is independent of the RAB GTPase RAB3. Moreover, we analyzed RAB3GAP1/2 in relation to the previously reported suppressive autophagy modulators FEZ1 and FEZ2 and demonstrate that both reciprocally regulate autophagy. In conclusion, we identify RAB3GAP1/2 as novel conserved factors of the autophagy and proteostasis network.

https://doi.org/10.4161/15548627.2014.994359