RPK118, a PX domain-containing protein, interacts with peroxiredoxin-3 through pseudo-kinase domains

Lingling Liu, Chenyi Yang, Jian Yuan, Xiujuan Chen, Jianing Xu, Youheng Wei, Jingchun Yang, Gang Lin, Long Yu

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)39-45
Number of pages7
JournalMolecules and Cells
Issue number1
StatePublished - Dec 1 2005


  • Co-immunoprecipitation
  • Co-localization
  • Early Endosome
  • PRDX3
  • RPK118
  • Yeast Two-Hybrid

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology


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