-
Tohru Yamashita,
Makoto Kamata,
Satoshi Endo,
Mitsuo Yamamoto,
Keiko Kakegawa,
Hiroyuki Watanabe,
Katsuhiko Miwa,
Toru Yamano,
Masaaki Funata,
Jyun-Ichi Sakamoto,
Akiyoshi Tani,
Clifford D Mol, Hua Zou,
Douglas R Dougan,
Biching Sang,
Gyorgy Snell,
Kohji Fukatsu
[show abstract]
[hide abstract]
ABSTRACT: The co-crystal structure of the human acetyl-coenzyme A 2 (ACC2) carboxyl transferase domain and the reported compound CP-640186 (1b) suggested that two carbonyl groups are essential for potent ACC2 inhibition. By focusing on enhancing the interactions between the two carbonyl groups and the amino acid residues Gly(2162) and Glu(2230), we used ligand- and structure-based drug design to discover spirolactones bearing a 2-ureidobenzothiophene moiety.
Bioorganic & medicinal chemistry letters 09/2011; 21(21):6314-8. · 2.65 Impact Factor
-
Kathleen Aertgeerts,
Robert Skene,
Jason Yano,
Bi-Ching Sang, Hua Zou,
Gyorgy Snell,
Andy Jennings,
Keiji Iwamoto,
Noriyuki Habuka,
Aki Hirokawa,
Tomoyasu Ishikawa,
Toshimasa Tanaka,
Hiroshi Miki,
Yoshikazu Ohta,
Satoshi Sogabe
[show abstract]
[hide abstract]
ABSTRACT: Aberrant signaling of ErbB family members, HER2 and EGFR, is implicated in many human cancers and HER2 expression is predictive
of human disease recurrence and prognosis. Small molecule kinase inhibitors of EGFR and of both HER2 and EGFR have received
approval for the treatment of cancer. We present the first high resolution crystal structure of the kinase domain of HER2
in complex with a selective inhibitor to understand protein activation, inhibition and function at the molecular level. HER2
kinase domain crystallizes as a dimer and suggests evidence for an allosteric mechanism of activation comparable to previously
reported activation mechanisms for EGFR and HER4. A unique Gly-rich region in HER2 following the α-helixC is responsible for
increased conformational flexibility within the active-site and could explain the low intrinsic catalytic activity previously
reported for HER2. In addition, we solved the crystal structure of the kinase domain of EGFR in complex with a HER2/EGFR
dual inhibitor. Comparison with previously reported inactive and active EGFR kinase domain structures gave insight into the
mechanism of HER2 and EGFR inhibition and may help guide the design and development of new cancer drugs with improved potency
and selectivity.
Journal of Biological Chemistry 03/2011; · 4.77 Impact Factor
-
Kathleen Aertgeerts,
Robert Skene,
Jason Yano,
Bi-Ching Sang, Hua Zou,
Gyorgy Snell,
Andy Jennings,
Keiji Iwamoto,
Noriyuki Habuka,
Aki Hirokawa,
Tomoyasu Ishikawa,
Toshimasa Tanaka,
Hiroshi Miki,
Yoshikazu Ohta,
Satoshi Sogabe
[show abstract]
[hide abstract]
ABSTRACT: Aberrant signaling of ErbB family members human epidermal growth factor 2 (HER2) and epidermal growth factor receptor (EGFR) is implicated in many human cancers, and HER2 expression is predictive of human disease recurrence and prognosis. Small molecule kinase inhibitors of EGFR and of both HER2 and EGFR have received approval for the treatment of cancer. We present the first high resolution crystal structure of the kinase domain of HER2 in complex with a selective inhibitor to understand protein activation, inhibition, and function at the molecular level. HER2 kinase domain crystallizes as a dimer and suggests evidence for an allosteric mechanism of activation comparable with previously reported activation mechanisms for EGFR and HER4. A unique Gly-rich region in HER2 following the α-helix C is responsible for increased conformational flexibility within the active site and could explain the low intrinsic catalytic activity previously reported for HER2. In addition, we solved the crystal structure of the kinase domain of EGFR in complex with a HER2/EGFR dual inhibitor (TAK-285). Comparison with previously reported inactive and active EGFR kinase domain structures gave insight into the mechanism of HER2 and EGFR inhibition and may help guide the design and development of new cancer drugs with improved potency and selectivity.
Journal of Biological Chemistry 03/2011; 286(21):18756-65. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Histone deacetylase 6 (HDAC6) is the only known HDAC with two potentially functional catalytic domains, yet the role towards substrate played by these two domains remains ambiguous. Most studies report HDAC6 activities measured using either immune complexes or in vitro translated products. Here, we characterize the activity of highly purified recombinant HDAC6, mutants with active site histidine mutations in each domain (H216A and H611A), and individual catalytic domains. The deacetylase activities of these proteins, as well as their kinetic parameters, were measured using histone, alpha-tubulin, and fluorogenic acetylated lysine as substrates. Mutant H216A only slightly lowers the catalytic rate. However, mutant H611A decreases the catalytic rate more than 5000-fold. The first domain expressed alone is not catalytically active. In contrast, the second domain shows only a modest decrease in substrate binding and product formation rate. Our results indicate that the in vitro deacetylase activity of HDAC6 resides in the C-terminal second catalytic domain.
Biochemical and Biophysical Research Communications 04/2006; 341(1):45-50. · 2.48 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The activity of the c-Kit receptor protein-tyrosine kinase is tightly regulated in normal cells, whereas deregulated c-Kit kinase activity is implicated in the pathogenesis of human cancers. The c-Kit juxtamembrane region is known to have an autoinhibitory function; however the precise mechanism by which c-Kit is maintained in an autoinhibited state is not known. We report the 1.9-A resolution crystal structure of native c-Kit kinase in an autoinhibited conformation and compare it with active c-Kit kinase. Autoinhibited c-Kit is stabilized by the juxtamembrane domain, which inserts into the kinase-active site and disrupts formation of the activated structure. A 1.6-A crystal structure of c-Kit in complex with STI-571 (Imatinib or Gleevec) demonstrates that inhibitor binding disrupts this natural mechanism for maintaining c-Kit in an autoinhibited state. Together, these results provide a structural basis for understanding c-Kit kinase autoinhibition and will facilitate the structure-guided design of specific inhibitors that target the activated and autoinhibited conformations of c-Kit kinase.
Journal of Biological Chemistry 08/2004; 279(30):31655-63. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The c-Kit proto-oncogene is a receptor protein-tyrosine kinase associated with several highly malignant human cancers. Upon binding its ligand, stem cell factor (SCF), c-Kit forms an active dimer that autophosphorylates itself and activates a signaling cascade that induces cell growth. Disease-causing human mutations that activate SCF-independent constitutive expression of c-Kit are found in acute myelogenous leukemia, human mast cell disease, and gastrointestinal stromal tumors. We report on the phosphorylation state and crystal structure of a c-Kit product complex. The c-Kit structure is in a fully active form, with ordered kinase activation and phosphate-binding loops. These results provide key insights into the molecular basis for c-Kit kinase transactivation to assist in the design of new competitive inhibitors targeting activated mutant forms of c-Kit that are resistant to current chemotherapy regimes.
Journal of Biological Chemistry 09/2003; 278(34):31461-4. · 4.77 Impact Factor
