title: Varp interacts with Rab38 and functions as its potential effector.
abstract: Varp, a novel protein containing a VPS9 domain and ankyrin repeats, can function as a guanine nucleotide exchange factor (GEF) of Rab21. We previously reported that Varp plays an important role in the regulation of endosome dynamics. To further investigate the function of Varp, a yeast two-hybrid screen was performed and Rab38 was identified as a Varp-associated protein. We demonstrate that Varp physically interacts with Rab38, and preferentially binds to the active GTP-bound form of Rab38 both in vitro and in vivo. Furthermore, Varp was shown to be recruited to Rab38-positive organelles in an ankyrin-repeat 1 (ANK1)-dependent manner. Our data demonstrate that Varp is a potential effector of Rab38. Together with our previous study, we propose Varp serves as both an effector and a GEF by interacting with different Rabs in mammalian cells.
authors.affiliation: Key Laboratory of Beijing, College of Life Science, Beijing Normal University, Beijing 100875, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Haiwei
authors.initials: H
authors.lastname: Zhang
authors.forename: Xinjun
authors.initials: X
authors.lastname: Zhang
authors.forename: Yinyin
authors.initials: Y
authors.lastname: Wang
authors.forename: Fangli
authors.initials: F
authors.lastname: Ren
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Zhang
authors.forename: Yonggong
authors.initials: Y
authors.lastname: Zhai
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Chang
mesh_terms: D000818:Animals; D002460:Cell Line; D004789:Enzyme Activation; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D020798:Two-Hybrid System Techniques; D020691:rab GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: C529611:ANKRD27 protein, human; D020662:Guanine Nucleotide Exchange Factors; D006160:Guanosine Triphosphate; C412058:RAB38 protein, human; D020691:rab GTP-Binding Proteins