title: Modeling of molecular interaction between apoptin, BCR-Abl and CrkL--an alternative approach to conventional rational drug design.
abstract: In this study we have calculated a 3D structure of apoptin and through modeling and docking approaches, we show its interaction with Bcr-Abl oncoprotein and its downstream signaling components, following which we confirm some of the newly-found interactions by biochemical methods. Bcr-Abl oncoprotein is aberrantly expressed in chronic myelogenous leukaemia (CML). It has several distinct functional domains in addition to the Abl kinase domain. The SH3 and SH2 domains cooperatively play important roles in autoinhibiting its kinase activity. Adapter molecules such as Grb2 and CrkL interact with proline-rich region and activate multiple Bcr-Abl downstream signaling pathways that contribute to growth and survival. Therefore, the oncogenic effect of Bcr-Abl could be inhibited by the interaction of small molecules with these domains. Apoptin is a viral protein with well-documented cancer-selective cytotoxicity. Apoptin attributes such as SH2-like sequence similarity with CrkL SH2 domain, unique SH3 domain binding sequence, presence of proline-rich segments, and its nuclear affinity render the molecule capable of interaction with Bcr-Abl. Despite almost two decades of research, the mode of apoptin's action remains elusive because 3D structure of apoptin is unavailable. We performed in silico three-dimensional modeling of apoptin, molecular docking experiments between apoptin model and the known structure of Bcr-Abl, and the 3D structures of SH2 domains of CrkL and Bcr-Abl. We also biochemically validated some of the interactions that were first predicted in silico. This structure-property relationship of apoptin may help in unlocking its cancer-selective toxic properties. Moreover, such models will guide us in developing of a new class of potent apoptin-like molecules with greater selectivity and potency.
authors.affiliation: Department of Molecular Cardiology, Lerner Research Institute/NB-50, Cleveland, Ohio, United States of America.
authors.forename: Soumya
authors.initials: S
authors.lastname: Panigrahi
authors.forename: Jörg
authors.initials: J
authors.lastname: Stetefeld
authors.forename: Jaganmohan R
authors.initials: JR
authors.lastname: Jangamreddy
authors.forename: Soma
authors.initials: S
authors.lastname: Mandal
authors.forename: Sanat K
authors.initials: SK
authors.lastname: Mandal
authors.forename: Marek
authors.initials: M
authors.lastname: Los
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D016923:Cell Death / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D019295:Computational Biology; D015536:Down-Regulation / Q000187:drug effects; D015195:Drug Design; D016044:Fusion Proteins, bcr-abl / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006860:Hydrogen Bonding / Q000187:drug effects; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000187:drug effects; D040681:Structural Homology, Protein; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000596:Amino Acids; C082869:CRKL protein; D036022:Capsid Proteins; D009687:Nuclear Proteins; C091717:VP3 protein, Chicken anemia virus; D016044:Fusion Proteins, bcr-abl