title: Crystal structure of the T315I Abl mutant in complex with the aurora kinases inhibitor PHA-739358.
abstract: Mutations in the kinase domain of Bcr-Abl are the most common cause of resistance to therapy with imatinib in patients with chronic myelogenous leukemia (CML). Second-generation Bcr-Abl inhibitors are able to overcome most imatinib-resistant mutants, with the exception of the frequent T315I substitution, which is emerging as a major cause of resistance to these drugs in CML patients. Structural studies could be used to support the drug design process for the development of inhibitors able to target the T315I substitution, but until now no crystal structure of the T315I Abl mutant has been solved. We show here the first crystal structure of the kinase domain of Abl T315I in complex with PHA-739358, an Aurora kinase inhibitor currently in clinical development for solid and hematologic malignancies. This compound inhibits in vitro the kinase activity of wild-type Abl and of several mutants, including T315I. The cocrystal structure of T315I Abl kinase domain provides the structural basis for this activity: the inhibitor associates with an active conformation of the kinase domain in the ATP-binding pocket and lacks the steric hindrance imposed by the substitution of threonine by isoleucine.
authors.affiliation: Nerviano Medical Sciences Srl-Oncology, Milan, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Modugno
authors.forename: Elena
authors.initials: E
authors.lastname: Casale
authors.forename: Chiara
authors.initials: C
authors.lastname: Soncini
authors.forename: Pamela
authors.initials: P
authors.lastname: Rosettani
authors.forename: Riccardo
authors.initials: R
authors.lastname: Colombo
authors.forename: Rosita
authors.initials: R
authors.lastname: Lupi
authors.forename: Luisa
authors.initials: L
authors.lastname: Rusconi
authors.forename: Daniele
authors.initials: D
authors.lastname: Fancelli
authors.forename: Patrizia
authors.initials: P
authors.lastname: Carpinelli
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Cameron
authors.forename: Antonella
authors.initials: A
authors.lastname: Isacchi
authors.forename: Jürgen
authors.initials: J
authors.lastname: Moll
mesh_terms: D064127:Aurora Kinases; D001549:Benzamides / Q000737:chemistry* / Q000378:metabolism*; D018360:Crystallography, X-Ray; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D006801:Humans; D000068877:Imatinib Mesylate; D008958:Models, Molecular; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology; D011485:Protein Binding; D047428:Protein Kinase Inhibitors / Q000737:chemistry* / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors*; D016315:Proto-Oncogene Proteins c-abl / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D011720:Pyrazoles / Q000737:chemistry* / Q000378:metabolism*; D011743:Pyrimidines / Q000494:pharmacology