Varp is a Rab21 guanine nucleotide exchange factor and regulates endosome dynamics

@article{Zhang2006VarpIA,
  title={Varp is a Rab21 guanine nucleotide exchange factor and regulates endosome dynamics},
  author={Xinjun Zhang and Xi He and Xin-Yuan Fu and Zhijie Chang},
  journal={Journal of Cell Science},
  year={2006},
  volume={119},
  pages={1053 - 1062}
}
The small GTPases Rab5 and Rab21 are closely related, and play essential roles in endocytic trafficking. Rab5 is regulated by VPS9-domain-containing guanine nucleotide exchange factors. Here, we describe a new VPS9-domain protein with ankyrin repeats, the VPS9-ankyrin-repeat protein (Varp). Varp interacts preferentially with GDP-bound Rab21 and has a much stronger guanine nucleotide exchange activity towards Rab21 than Rab5. Furthermore, RNAi-mediated depletion of endogenous Varp significantly… Expand
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