title: RPK118, a PX domain-containing protein, interacts with peroxiredoxin-3 through pseudo-kinase domains.
abstract: RPK118 is a sphingosine kinase-1-binding protein that has been implicated in sphingosine 1 phosphate-mediated signaling. It contains a PX (phox homology) domain and two pseudo-kinase domains, and co-localizes with sphingosine kinase-1 on early endosomes. In this study we identified a novel RPK118-binding protein, PRDX3 (peroxiredoxin-3), by yeast two-hybrid screening. The interaction between these proteins was confirmed by pull-down assays and co-immunoprecipitation experiments. Deletion studies showed that RPK118 interacted with PRDX3 through its pseudokinase domains, and with early endosomes through its PX domain. Double immunofluorescence experiments demonstrated that PRDX3 co-localized with RPK118 on early endosomes in COS7 cells. PRDX3 is a member of the antioxidant family of proteins synthesized in the cytoplasm and functioning in mitochondria. Our findings indicate that RPK118 is a PRDX3-binding protein that may be involved in transporting PRDX3 from the cytoplasm to its mitochondrial site of function or to other membrane structures via endosome trafficking.
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai 200433, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Liu
authors.forename: Chenyi
authors.initials: C
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Yuan
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Chen
authors.forename: Jianing
authors.initials: J
authors.lastname: Xu
authors.forename: Youheng
authors.initials: Y
authors.lastname: Wei
authors.forename: Jingchun
authors.initials: J
authors.lastname: Yang
authors.forename: Gang
authors.initials: G
authors.lastname: Lin
authors.forename: Long
authors.initials: L
authors.lastname: Yu
mesh_terms: D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000737:chemistry / Q000378:metabolism*; D010544:Peroxidases; D061105:Peroxiredoxin III; D054464:Peroxiredoxins; D010770:Phosphotransferases / Q000235:genetics*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000096:biosynthesis; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D019893:Ribosomal Protein S6 Kinases / Q000737:chemistry / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D000099157:Sphingosine Kinase
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009363:Neoplasm Proteins; D010544:Peroxidases; D061105:Peroxiredoxin III; D054464:Peroxiredoxins; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); D019893:Ribosomal Protein S6 Kinases; D000099157:Sphingosine Kinase; C516115:PRDX3 protein, human; C467003:RPS6KC1 protein, human