Chiharu Tokunaga
Member of Kazuyoshi Yonezawa's Kobe team that co-discovered raptor, and first author of a 2004 review on how mTOR combines amino acid and energy signals
Assistant professor (joshu), Biosignal Research Center, Kobe University (KAKEN record 2002–2004), Kazuyoshi Yonezawa group (PubMed records 2000–2006, at the time of the studies)
Chiharu Tokunaga is a co-author of the 2002 Cell paper from Kobe University (HARA2002) that, together with a Boston study in the same issue, reported raptor, the partner protein that defines mTORC1, the growth-control complex. The Kobe team showed that raptor is needed for mTOR to act on 4E-BP1 and S6 kinase and that silencing raptor in worms mimics loss of TOR. Tokunaga is also a co-author of the 2003 follow-up (NOJ2003), which found that raptor holds these two targets through a short TOS motif and so presents them to the kinase.
In 2004 Tokunaga was first author, with Ken-ichi Yoshino and Kazuyoshi Yonezawa, of a review in Biochemical and Biophysical Research Communications explaining how mTOR brings together two kinds of information, whether amino acids are available and whether the cell has enough energy. PubMed lists Tokunaga at the Biosignal Research Center of Kobe University on that review.
Other PubMed records from the same group, from 2000 to 2006, include work on the tail region of mTOR that the enzyme needs to work, on a leucine derivative that blocks amino acid signalling to mTOR, on how the Hsp90 inhibitor geldanamycin disrupts the mTOR-raptor pathway, and on the motifs of 4E-BP1 that bind raptor.
Japan's national research grant database (KAKEN) lists Tokunaga as an assistant professor at the Biosignal Research Center of Kobe University from 2002 to 2004, with grants on the crosstalk between mTOR, which senses nutrients, and AMPK, which senses the cell's energy level. The record lists no later affiliation, so a current position could not be confirmed.
Milestones in the Atlas
A selection, not a full bibliography: only papers that meet the Atlas inclusion criteria.
| Year | Evidence | Study |
|---|---|---|
| 2002 | M | Raptor, a binding partner of target of rapamycin (TOR), mediates TOR action HARA2002 Co-author: part of the Kobe team that co-discovered raptor and showed it is needed for mTOR to act on 4E-BP1 and S6 kinase. |
| 2003 | M | The mammalian target of rapamycin (mTOR) partner, raptor, binds the mTOR substrates p70 S6 kinase and 4E-BP1 through their TOR signaling (TOS) motif NOJ2003 Co-author: contributed to the study showing that raptor binds mTOR substrates through their TOS motif. |
Co-authors in the Atlas 7
People with a profile here who share at least one study with Chiharu Tokunaga.
ShowHide
- Joseph Avruch 2 shared studies Showed in 1998 that amino acids, not only insulin, are needed for mTOR to activate S6K1 and 4E-BP1. His Massachusetts General Hospital group, with Kazuyoshi Yonezawa's lab in Kobe, then co-discovered raptor in 2002 and found that Rheb binds mTOR directly
- Kazuyoshi Yonezawa 2 shared studies Led the Kobe University group that co-discovered raptor in 2002, in parallel with the Sabatini lab. His team then showed that raptor binds mTOR's substrates through their TOS motif and that PRAS40 is itself an mTORC1 substrate
- Kenta Hara 2 shared studies Showed in 1998 that amino acids are needed for mTOR to activate S6K1 and 4E-BP1, and as first author co-discovered raptor in 2002
- Noriko Oshiro-Rapley 2 shared studies In one of several 2007 studies, identified PRAS40 as a raptor-bound mTORC1 substrate that gates access to mTORC1's other substrates
- Sujuti Hidayat 2 shared studies Member of Kazuyoshi Yonezawa's Kobe team that co-discovered raptor and worked out how mTOR senses amino acids, and first author of a study showing that a leucine derivative can block amino acid-mTOR signalling
- Hiroki Nojima First author of the 2003 Kobe study showing that raptor grabs mTOR's targets through a short TOS motif, the docking step that lets mTORC1 reach its substrates
- Xiaomeng Long Discovered that Rheb binds directly to the mTOR kinase domain and switches it on
Every researcher with a profile →
Thank you. That helps us know which pages have been read by someone who knows the work.
Thank you. We will check it and correct the page.
Thank you. Your answer was counted anonymously.