New splicing variants of mitochondrial Rho GTPase-1 (Miro1) transport peroxisomes

Kanji Okumoto, Tatsuaki Ono, Ryusuke Toyama, Ayako Shimomura, Aiko Nagata, Yukio Fujiki

Research output: Contribution to journalArticlepeer-review

41 Citations (Scopus)


Microtubule-dependent long-distance movement of peroxisomes occurs in mammalian cells. However, its molecular mechanisms remain undefined. In this study, we identified three distinct splicing variants of human mitochondrial Rho GTPase-1 (Miro1), each containing amino acid sequence insertions 1 (named Miro1-var2), 2 (Miro1-var3), and both 1 and 2 (Miro1-var4), respectively, at upstream of the transmembrane domain. Miro1-var4 and Miro1-var2 are localized to peroxisomes in a manner dependent on the insertion 1 that is recognized by the cytosolic receptor Pex19p. Exogenous expression of Miro1-var4 induces accumulation of peroxisomes at the cell periphery and augments long-range movement of peroxisomes along microtubules. Depletion of all Miro1 variants by knocking down MIRO1 suppresses the long-distance movement of peroxisomes. Such abrogated movement is restored by reexpression of peroxisomal Miro1 variants. Collectively, our findings identify for the first time peroxisome-localized Miro1 variants as adapter proteins that link peroxisomes to the microtubule-dependent transport complexes including TRAK2 in the intracellular translocation of peroxisomes in mammalian cells.

Original languageEnglish
Pages (from-to)619-633
Number of pages15
JournalJournal of Cell Biology
Issue number2
Publication statusPublished - Feb 1 2018

All Science Journal Classification (ASJC) codes

  • Cell Biology


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