showing 5 related works from this author
RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy
2014
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 an…
RAB18 Loss Interferes With Lipid Droplet Catabolism and Provokes Autophagy Network Adaptations
2020
Autophagy is dependent on appropriate lipid supply for autophagosome formation. The regulation of lipid acquisition and the autophagy network response to lipid-limiting conditions are mostly elusive. Here, we show that the knockout of the RAB GTPase RAB18 interferes with lipid droplet catabolism, causing an impaired fatty acid release. The resulting reduced lipid-droplet-derived lipid availability influences autophagy and provokes adaptive modifications of the autophagy network. These adjustments include increased expression and phosphorylation of ATG2B as well as augmented formation of the ATG12-ATG5 conjugate. Moreover, ATG9A shows an enhanced phosphorylation at amino acid residues tyrosi…
RAB18 impacts autophagy via lipid droplet-derived lipid transfer and is rescued by ATG9A
2018
AbstractAutophagy is a lysosomal degradation pathway that mediates protein and organelle turnover and maintains cellular homeostasis. Autophagosomes transport cargo to lysosomes and their formation is dependent on an appropriate lipid supply. Here, we show that the knockout of the RAB GTPase RAB18 interferes with lipid droplet (LD) metabolism, resulting in an impaired fatty acid mobilization. The reduced LD-derived lipid availability influences autophagy and provokes adaptive modifications of the autophagy network, which include increased ATG2B expression and ATG12-ATG5 conjugate formation as well as enhanced ATG2B and ATG9A phosphorylation. Phosphorylation of ATG9A directs this transmembra…
The RAB GTPase RAB18 modulates macroautophagy and proteostasis
2017
Macroautophagy is a conserved degradative pathway and its deterioration is linked to disturbances in cellular proteostasis and multiple diseases. Here, we show that the RAB GTPase RAB18 modulates autophagy in primary human fibroblasts. The knockdown of RAB18 results in a decreased autophagic activity, while its overexpression enhances the degradative pathway. Importantly, this function of RAB18 is dependent on RAB3GAP1 and RAB3GAP2, which might act as RAB GEFs and stimulate the activity of the RAB GTPase. Moreover, the knockdown of RAB18 deteriorates proteostasis and results in the intracellular accumulation of ubiquitinated degradation-prone proteins. Thus, the RAB GTPase RAB18 is a positi…
RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy
2015
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 an…