我々は、世界に先駆け、インスリン受容体 cDNAを単離した(Cell, 1985. Ebina et al.)。そして、インスリン受容体のチロシンキナーゼ活性がインスリン作用発現に必須であることを証明し(Proc. Natl. Acad. Sci. USA, 1987)、受容体遺伝子上でチロシンキナーゼドメインが欠失している糖尿病患者を発見した(Science, 1989)。また、インスリンの「細胞内へのグルコース取り込み促進」作用には、PI 3-キナーゼの活性化が必須であることを世界に先駆けて報告した(BBRC, 1993., Proc. Natl. Acad. Sci. USA, 1995.)。さらにその下流のAkt2がこの作用発現に重要であることをRNAiの手法を用い明らかにした(J.Biol.Chem., 2003)。また、2型糖尿病発症には、“肝臓におけるインスリン作用不全”が重要であることを見出した(Nature Genetics, 1998)。インスリン作用の中で最も重要なものの1つが膜を12回貫通するGLUT4（Glucose Transporter Type 4;インスリン反応性グルコーストランスポーター）のトランスロケーションとその結果起こるグルコースの細胞内への取り込み促進である。我々は世界で初めて、GLUT4のトランスロケーションを定量的に測定する画期的な方法を考案した(J.Biol.Chem., 1993)。この新しい方法論により、GLUT4トランスロケーションには、PI3-キナーゼとAkt2の活性化が必須であること、GLUT4はインスリンによりのみ制御されると考えられていたが、三量体GタンパクのGqを活性化するような生理活性物質によってもおこることを発見した。(J.Biol.Chem.,1996, Diabetes 1998)。

我々は細胞増殖因子に共通なシグナル伝達因子であるPI 3-キナーゼがインスリンによるGLUT4のトランスロケーションに必須であること、そしてPDGFやEGFなどのPI 3-キナーゼを活性化する細胞増殖因子も培養細胞レベルではGLUT4のトランスロケーションを引き起こし、細胞内へのグルコースの取り込みを促進することを世界に先駆けて発見した(J.Biol.Chem., 1999)。しかし、インスリンと異なり、PDGF などを生体に投与しても血糖値は下がらない。その原因は骨格筋においてはインスリンレセプターは多く発現しているが、PDGFレセプターはほとんど発現していないためであり、PI 3-キナーゼ以後のGLUT4のトランスロケーションを引き起こすまでの細胞内シグナルは存在していると考えた。そこでトランスジェニックの手法で骨格筋で PDGFレセプターを特異的に発現しているトランスジェニックマウスを確立した。そしてPDGF、インスリンなどを投与して血糖値降下などの解析を行った。

その結果、このトランスジェニックマウスではインスリンと同様PDGF投与によって骨格筋へのグルコースの取り込みは明らかに促進したが、血糖値の低下は見られなかった(Diabetes 2004)。この事実はインスリンは骨格筋におけるグルコースの取り込み促進と共に、肝臓におけるグルコース放出抑制を非常に早期に同時に行う。従って、血糖値低下の原因は、骨格筋へのグルコース取り込み促進だけでなく、早期に起こる肝からのグルコース放出抑制も重要である事が明らかとなった。今後肝でのインスリン作用も血糖低下には重要である事が分かってきたので解明を進める。

最近、糖尿病患者の血清中にはインスリン受容体のαサブユニット（インスリン結合ドメイン）が切断され、遊離している事を世界で初めて発見した。糖尿病モデルマウスでも高血糖になると共に血中に多くのインスリン受容体αサブユニットが遊離されている事を確認した（論文投稿中）。この事実は糖尿病研究に全く新しい展開を与えるものである。

業　績

1    Functional Analysis of PIK3CA Gene Mutations in Human Colorectal Cancer

                                                                                                                  Cancer Research;65(11):4562-7.  (2005)                                                                                                                  IF:8.649

                                                                                                                  Tsuneo Ikenoue, Fumihiko Kanai1, Yohko Hikiba, Toshiyuki Obata, Yasuo Tanaka, Jun Imamura, Miki Ohta, Jazag Amarsana, Bayasi Guleng, Keisuke Tateishi, Yoshinari Asaoka, Masayuki Matsumura, Takao Kawabe and Masao Omata

2    ERK1/2 activation by angiotensin II inhibits insulin-induced glucose uptake in vascular smooth muscle cells

Experimental Cell Research;308(2):291-9.  (2005)                                    IF:3.949

Yuki Izawa, Masanori Yoshizumi, Yoshiko Fujita, Nermin Ali, Yasuhisa Kanematsu, Keisuke Ishizawa, Koichiro Tsuchiya, Toshiyuki Obata, Yousuke Ebina and Shuhei Tomita

3     Platelet-derived growth factor stimulates glucose transport in skeletal muscles of transgenic mice specifically expressing PDGF receptor in the muscle, but does not affect blood glucose levels

Diabetes 53, 2776-2786 (2004)                                                                    IF:8.298

Tomoyuki Yuasa, Rei Kakuhata, Kazuhiro Kishi, Toshiyuki Obata, Yasuo Shinohara, Yoshimi Bando, Keisuke Izumi, Fumiko Kajiura, Mitsuru Matsumoto and Yousuke Ebina

4     Protein Phosphatase 2A negatively Regulates insulin's Metabolic Signaling Pathway by Inhibiting Akt (Protein Kinase B) Activity in 3T3-L1 Adipocytes

Mol. Cell. Biol. 241(19) 8778-8789 (2004)                                                 IF:8.142

Satoshi Ugi, Takeshi Imamura, Hiroshi Maegawa, Katsuya Egawa, Takeshi Yoshizaki, Kun Shi, Toshiyuki Obata, Yousuke Ebina, Atsunori Kashiwagi and Jerrold M. Olefsky

5     KATP Channel Knockout Mice with transgenic Mice Expressing a Dominant-Negative Form of Human Insulin receptor have Glucose Intolerance but not Diabetes

Endocrine J. 51(2) 133-144 (2004)                                                           IF:1.045

Yoshiko Kanezaki, Toshiyuki Obata, Rie Matsushima, Asako Minami, Tomoyuki Yuasa, Kazuhiro Kishi, Yoshimi Bando, Hisanori Uehara, Keisuke Izumi, Tasuku Mitani, Mitsuru Matsumoto, Yukari Takeshita, Yutaka Nakaya, Toshio Matsumoto and Yousuke Ebina

6     ZFH4 protein is expressed in many neurons of developing rat brain.

                                                                                                                J. Comp. Neurol. 482(1), 33-49 (2004)                                                                                                                  IF:3.672

                                                                                                                Shigeharu Nogami, Yoko Ishii, Makoto Kawaguchi, Nobuo Sakata, Takeshi Oya, Kiyoshi Takagawa, Masahiko Kanamori, Hemragul Sabit, Toshiyuki Obata, Tomoatsu Kimura and Masakiyo Sasahara

7     Inhibition of Akt kinase activity by a peptide spanning the beta A strand of the protooncogene TCL1

                                                                                                                J Biol Chem. 279(51), 53407-53418 (2004)                                                                                                                  IF:6.482

                                                                                                                Makoto Hiromura, Futoshi Okada, Toshiyuki Obata, Daniel Auguin, Takeshi Shibata, Christian Roumenstand and Masayuki Noguchi

8     The phosphatidylinositol-3 Kinase Pathway Regulates Bladder Cancer Cell Invasion

                                                                                                                The British Journal of Urology 93(1), 143-150 (2004)                                                                                          IF:1.642

                                                                                                                Xiuli Wu, Toshiyuki Obata, Qiratulanne Khan, Ralph A. Highshaw, Ralph de Vere White and Colleen Sweeney

9     Increased insulin sensitivity and hypoinsulinemia in APS knockout mice

Diabetes 52, 2657-2665 (2003)                                                                  IF:8.298

Asako Minami, Masanori Iseki, Kazuhiro Kishi, Miao Wang, Makoto Ogura, Noboru Furukawa, Sanae Hayashi, Mizuki Yamada, Toshiyuki Obata, Yukari Takeshita, Yutaka Nakaya, Yoshimi Bando, Keisuke Izumi, Shonna A. Moodie, Fumiko Kajiura, Mitsuru Matsumoto, Kiyoshi Takatsu, Satoshi Takaki and Yousuke Ebina

10    Injection of the insulin receptor alpfa subunit increases blood glucose levels in mice

Biochem. Biophys. Res. Commun. 309(30) 572-577 (2003)                      IF:2.836

Yoshiko Kanezaki, Rie Matsushima, Toshiyuki Obata, Yutaka Nakaya, Toshio Matsumoto and Yousuke Ebina

11   Use of RNA-interference-mediated gene silencing and adenoviral overexpression to Elucidate the roles of AKT/PKB-isoforms in insulin actions

J. Biol. Chem. 278, 28312-28323 (2003)                                                   IF:6.482

Toshiyuki Obata, Takashi Katome, Rie Matsushima, Norihisa Masuyama, Lewis C. Cantley, Yukiko Gotoh, Kazuhiro Kishi, Hiroshi Shiota and Yousuke Ebina

12   Shikonin Stimulates Glucose Uptake in 3T3-L1 Adipocytes via an Insulin-Independent Tyrosine Kinase Pathway

Biochem. Biophys. Res. Commun. 292, 642-651 (2002)                            IF:2.836

Reiko Kamei, Yoshinori Kitagawa, Michinori Kadokura, Fumiyuki Hattori, Osamu Hazeki, Yousuke Ebina, Tatsuro Nishihara and Shinzo Oikawa

13    Membrane localization of 3-phosphoinositide-dependent protein kinase-1 stimulates activities of Akt and Atypical PKC, but does not stimulate glucose transport and glycogen synthesis in 3T3-L1 adipocytes 

                                                                                                                J. Biol. Chem. 277, 38863-38869 (2002)                                                                                                                IF:6.482

                                                                                                                Katusya Egawa, Hiroshi Maegawa, Kun Shi, Takaaki Nakamura, Toshiyuki Obata, Takeshi Yoshizaki, Katsutaro Morino, Shinya Shimizu, Yoshihiko, Nishio, Eiji Suzuki, Atsunori Kashiwagi

14   Akt enhances Mdm2-mediated ubiquitination and degradation of p53

                                                                                                                J. Biol. Chem. 277, 21843-21850 (2002)                                                                                                                IF:6.482

                                                                                                                Yoko Ogawara, Shohei Kishishita, Toshiyuki Obata, Yuko Isazawa, Toshiaki Suzuki, Keiji Tanaka, Norihisa Masuyama and Yukiko Gotoh

15   Akt/PKB promotes organ growth in transgenic mice

                                                                                                                Mol. Cell. Biol. 22, 2799-2809 (2002)                                                                                                                IF:8.142

                                                                                                                Tetuo Shioi, Julie R. McMullen, Peter M. Kang, Pamela S. Douglas, Toshiyuki Obata, Thomas F. Frank, Lewis C. Cantley and Seigo Izumo

16   Differential regulation of Akt kinase isoforms by the members of the TCL1 oncogene family

                                                                                                                J. Biol. Chem. 277, 3743-3751 (2002)                                                                                                                IF:6.482

       Jaromo Laine, Gerald Kunstle, Toshiyuki Obata and Masayuki Noguchi

17   Effects of losartan in combination with or without exercise on insulin resistance in Otsuka Long-Evans Tokushima Fatty rats

Eur. J. Pharmacol. 430, 359-367 (2001)                                                   IF:2.352

Keisuke Ishizawa, Masanori Yoshizumi, Koichiro Tsuchiya, Eiko Takishita, Yutaka Nakaya, Kazuhiro Kishi, Yousuke Ebina, Hitoshi Houchi, Kazuo Minakuchi and Toshiaki Tamaki

18   Antisense GLUT-1 protects mesangial cells from glucose induction of GLUT-1 and fibronectin expression

Am J Physiol Renal Physiol 280, F657-666 (2001)                                    IF:4.344

Charles W. Heilig, Jeffrey I. Kreisberg, Svend Freytag, Takashi Murakami, Yousuke Ebina, Lirong Guo, Kathleen Heilig, Robert Loberg, Xuan qu, Ying Jin, Douglas Henry, and Frank C. Brosius III

19   Identification of a cis ? Acting Element and a Noveltrans ? Acting Factor of the Human Insulin Receptor Gene in HepG2 and Rat Liver Cells

Biochem. Biophys. Res. Commun. 280, 428-434 (2001)                            IF:2.836

Kazuaki Yoshizato, Tetsuya Shirotani, Noboru Furukawa, Tetsuya Taguchi, Hiroyuki Motoshima, Tetsushi Toyonaga, Yoshiaki Hirashima, Junji Kawashima, Yousuke Ebina, Motoaki Shichiri and Eiichi Araki

20   A motif-based profile scanning approach for genome-wide prediction of signaling pathways

                                                                                                                Nature Biotechnol. 19, 348-353 (2001)                                                                                                                 IF:17.721

                                                                                                                Michael B. Yaffe, German G. Leparc, Jack Lai, Toshiyuki Obata, Stefano Volinia and Lewis C. Cantley

21    AMP-activated protein kinase is activated by the stimulations of Gq-coupled receptors

Biochem. Biophys. Res. Commun. 276, 16-22 (2000)                               IF:2.836

Kazuhiro Kishi, Tomoyuki Yuasa, Asako Minami, Mizuki Yamada, Akifumi Hagi, Hideki Hayashi, Bruce E. Kemp, Lee A. Witters and Yousuke Ebina

22   Activation of G-protein coupled fMLP or PAF receptor directly triggers glucose transporter type 1 (GLUT1) translocation in Chinese hamster ovary (CHO) cells stably expressing fMLP or PAF receptor

The Journal of Medical Investigation 47(1-2) (2000)                               IF:0

Akifumi Hagi, Hideki Hayashi, Kazuhiro Kishi, Lihong Wang and Yousuke Ebina

23   Overexpression of wild-type Akt1 promoted insulin-stimulated p70S6 kinase (p70S6K) activity and affected GSK3b regulation, but did not promote insulin-stimulated GLUT4 translocation or glucose transport in L6 myotubes

The Journal of Medical Investigation 47(1-2) (2000)                               IF:0

Satoshi Noda, Kazuhiro Kishi, Tomoyuki Yuasa, Hideki Hayashi, Tetuo Ohnishi, Ikuko Miyata, Hiromu Nishitani and Yousuke Ebina

24   Gi-mediated translocation of GLUT4 is independent of p85/p110a?and p110g phosphoinositide 3-kinases but might involve the activation of Akt kinase

Biochem. J. 345, 543-555 (2000)                                                              IF:4.101

Lihong Wang, Hideki Hayashi, Kazuhiro Kishi, Luping Huang, Akifumi Hagi, Keisuke Tamaoka, Phillip T. Hawkins and Yousuke Ebina 

25   The protooncogene TCL1 is an Akt kinase coactivator

                                                                                                                Mol. Cell. 6, 395-407 (2000)       IF:16.835

                                                                                                               Jarmo Laine, Gerald Kunstle, Toshiyuki Obata, Ma Sha and Masayuki Noguchi

26   MAP kinase pathways activated by stress: the p38 MAPK pathway

       Crit. Care Med. 28, N67-77 (2000)                                                            IF:4.195

       Toshiyuki Obata, Glenn E. Brown and Michael B. Yaffe

27   Peptide and Protein Library Screening Defines Optimal Substrate Motifs for AKT/PKB

      J. Biol. Chem. 275, 36108-36115 (2000)                                                      IF:6.482

      Toshiyuki Obata, Michael B. Yaffe, German G. Leparc, Elizabeth T. Piro, Hiroshi Maegawa, Atsunori Kashiwagi, Ryuichi Kikkawa and Lewis C. Cantley

28    Association of Stomatin (Band 7.2b) with Glut 1 Glucose Transporter

Archives of Biochemistry and Biophysics 372(1), 173-178 (1999)             IF:2.338

Jin-Zhong Zhang, Hideki Hayashi, Yousuke Ebina, Rainer Prohaska and Faramarz Ismail-Beigi

29   Fluoromicroscopic detection of myc-tagged GLUT4 on the cell surface. Co-localization of the translocated GLUT4 with rearranged actin by insulin teatment in CHO cells and L6 myotubes

The Journal of Medical Investigation 46(3-4) (1999)                               IF:0

Yoshihiko Asahi, Hideki Hayashi, Lihong Wang and Yousuke Ebina

30   GLUT-4myc ectopic expression in L6 myoblasts generates a GLUT-4-specific pool conferring insulin sensitivity

Am. J. Physiol. 277, E572-E578 (1999)                                                     IF:3.828

Atsunori Ueyama, Karen L. Yaworsky, Qinghua Wang, Yousuke Ebina and Amira Klip

31   Mutation of Tyrosine 960 within the Insulin Receptor Juxtamembrane Domain Impairs Glucose Transport but Dose Not Inhibit Ligand-mediated Phosphorylation of Insulin Receptor Substrate-2 in 3T3-L1 Adipocytes

J. Biol. Chem. 274, 12075-12080 (1999)                                                   IF:6.482

Oleg V. Chaika, Nina Chaika, Deanna J. Volle, Hideki Hayashi, Yousuke Ebina, Ling-Mei Wang, Jacalyn H. Piece and Robert E. Lewis 

32   Transient Effect of Platelet-derived Growth Factor (PDGF) on GLUT4 Translocation in 3T3-L1 Adipocytes

J. Biol. Chem. 274, 19246-19253 (1999)                                                   IF:6.482

Lihong Wang, Hideki Hayashi and Yousuke Ebina 

33   Effect of growth hormone on the translocation of GLUT4 and its relation to insulin-like and anti-insulin action

Biochimica et Biophysica Acta 1404, 451-456 (1998)                               IF:3.594

Ichiro Yokota, Hideki Hayashi, Junko Matsuda, Takahiko Saijo, Etsuo Naito, Michinori Ito, Yousuke Ebina and Yasuhiro Kuroda

34   Impaired glucose tolerance in mice with a targeted impairment of insulin action in muscle and adipose tissue

Nature Genetics. 20, 294-298 (1998)                                                        IF:26.494

Davide Lauro, Yoshiaki Kido, Arthur L. Castle, Mary-Jane Zarnowski, Hideki Hayashi, Yousuke Ebina and Domenico Accili

35   Rapid stimulation of glucose transport by mitochondrial uncoupling depends in part on cytosolic Ca²⁺ and cPKC

Am. J. Physiol. 275(6 Pt1), C1487-1497 (1998)                                         IF:3.828

Zayna Khayat, Theodoros Tsakiridis, Atsunori Ueyama, Romel Somwar, Yousuke Ebina and Amira Klip

36   Reconstitution of Insulin Signaling Pathways in Rat 3Y1 Cells Lacking Insulin Receptor and Insulin Receptor Substrate-1

J. Biol. Chem. 273, 25347-25355 (1998)                                                   IF:6.482

Takanobu Imanaka, Hideki Hayashi, Kazuhiro Kishi, Lihong Wang, Kazuo Ishii, Osamu Hazeki, Toshiaki Katada and Yousuke Ebina

37   GLUT4 translocation by insulin in intact muscle cells: detection by a fast and quantitative assay

FEBS Letters 427, 193-197 (1998)                                                            IF:3.609

Qinghua Wang, Zayna Khayat, Kazuhiro Kishi, Yousuke Ebina and Amira Klip

38   Insulin enhances macrophage scavenger receptor-mediated endocytic uptake of advanced glycation end products

J. Biol. Chem. 273, 8630-8637 (1998)                                                       IF:6.482

Hiroyuki Sano, Takayuki Higashi, Kenshi Matsumoto, Jukka Melkko, Yoshiteru Jinnouchi, Kazuyoshi Ikeda, Yousuke Ebina, Hideichi Makino, Bard Smedsrod and Seikoh Horiuchi

39    Bradykinin directly triggers GLUT4 translocation via an insulin-independent pathway

Diabetes 47, 550-558 (1998)                                                                     IF:8.298

Kazuhiro Kishi, Naoko Muromoto, Yutaka Nakaya, Ikuko Miyata, Akifumi Hagi, Hideki Hayashi and Yousuke Ebina

40    Transcriptional activation of the Glut1 gene in response to oxidative stress in L6 myotubes

J. Biol. Chem. 272, 33367-33372 (1997)                                                  IF:6.482

Nitzan Kozlovsky, Assaf Rudich, Ruth Potashnik, Yousuke Ebina, Takashi Murakami and Nava Bashan

41   Hyperinsulinemia but no diabetes in transgenic mice homozygously expressing the tyrosine kinase-deficient human insulin receptor

Biochem. Biophys. Res. Commun. 240, 446-451 (1997)                            IF: 2.836

Lihong Wang, Naoko Muromoto, Hideki Hayashi, Yasumasa Mitani, Hisanori Uehara, Keisuke Izumi and Yousuke Ebina

42   Acute stimulation of glucose metabolism in mice by leptin treatment

Nature 389, 374-377 (1997)                                                                      IF:30.979

Seika Kamohara, Remy Burcelin, Jeffrey L. Halaas, Jeffrey M. Friedman and Maureen J. Charron