Developmentally regulated GTP-binding protein 2 is required for stabilization of Rac1-positive membrane tubules

• Published in: Biochemical and biophysical research communications Vol. 493; no. 1; pp. 758 - 764
• Main Authors: Mani, Muralidharan, Lee, Unn Hwa, Yoon, Nal Ae, Yoon, Eun Hye, Lee, Byung Ju, Cho, Wha Ja, Park, Jeong Woo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 04.11.2017
• Subjects: Animals; Cell Membrane - metabolism; Cells, Cultured; DRG2; Endosomes - metabolism; Fibroblasts; GTP-Binding Proteins - metabolism; Humans; MCF-7 Cells; Membrane tubule; Mice; Neuropeptides - metabolism; Phospholipids - metabolism; PIP; Rac1; rac1 GTP-Binding Protein - metabolism; DRG2; Rac1; PIP; Membrane tubule
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2017.08.110

Previously we have reported that developmentally regulated GTP-binding protein 2 (DRG2) localizes on Rab5 endosomes and plays an important role in transferrin (Tfn) recycling. We here identified DRG2 as a key regulator of membrane tubule stability. At 30 min after Tfn treatment, DRG2 localized to membrane tubules which were enriched with phosphatidylinositol 4-monophosphate [PI(4)P] and did not contain Rab5. DRG2 interacted with Rac1 more strongly with GTP-bound Rac1 and tubular localization of DRG2 depended on Rac1 activity. DRG2 depletion led to destabilization of membrane tubules, while ectopic expression of DRG2 rescued the stability of the membrane tubules in DRG2-depleted cells. Our results reveal a novel mechanism for regulation of membrane tubule stability mediated by DRG2. •DRG2 localizes to membrane tubules enriched with PI(4)P.•Tubular localization of DRG2 depends on Rac1 activity.•DRG2 depletion destabilizes membrane tubules.•Overexpression of DRG2 rescued the stability of membrane tubules in DRG2 depleted cells.