title: Direct inhibition of oncogenic KRAS by Bacillus pumilus ribonuclease (binase).
abstract: RAS proteins function as molecular switches that transmit signals from cell surface receptors into specific cellular responses via activation of defined signaling pathways (Fang, 2015). Aberrant constitutive RAS activation occurs with high incidence in different types of cancer (Bos, 1989). Thus, inhibition of RAS-mediated signaling is extremely important for therapeutic approaches against cancer. Here we showed that the ribonuclease (RNase) binase, directly interacts with endogenous KRAS. Further, molecular structure models suggested an inhibitory nature of binase-RAS interaction involving regions of RAS that are important for different aspects of its function. Consistent with these models, phosphorylation analysis of effectors of RAS-mediated signaling revealed that binase inhibits the MAPK/ERK signaling pathway. Interestingly, RAS activation assays using a non-hydrolysable GTP analog (GTPγS) demonstrated that binase interferes with the exchange of GDP by GTP. Furthermore, we showed that binase reduced the interaction of RAS with the guanine nucleotide exchange factor (GEF), SOS1. Our data support a model in which binase-KRAS interaction interferes with the function of GEFs and stabilizes the inactive GDP-bound conformation of RAS thereby inhibiting MAPK/ERK signaling. This model plausibly explains the previously reported, antitumor-effect of binase specific towards RAS-transformed cells and suggests the development of anticancer therapies based on this ribonuclease.
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal (Volga-Region) University, Kremlevskaya str. 18, 420008, Kazan, Russia.
authors.forename: Olga N
authors.initials: ON
authors.lastname: Ilinskaya
authors.affiliation: LOEWE Research Group Lung Cancer Epigenetic, Max-Planck-Institute for Heart and Lung Research, Parkstr. 1, 61231 Bad Nauheim, Germany.
authors.forename: Indrabahadur
authors.initials: I
authors.lastname: Singh
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal (Volga-Region) University, Kremlevskaya str. 18, 420008, Kazan, Russia. Electronic address: lenatimonina@rambler.ru.
authors.forename: Elena
authors.initials: E
authors.lastname: Dudkina
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal (Volga-Region) University, Kremlevskaya str. 18, 420008, Kazan, Russia.
authors.forename: Vera
authors.initials: V
authors.lastname: Ulyanova
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal (Volga-Region) University, Kremlevskaya str. 18, 420008, Kazan, Russia.
authors.forename: Airat
authors.initials: A
authors.lastname: Kayumov
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal (Volga-Region) University, Kremlevskaya str. 18, 420008, Kazan, Russia; LOEWE Research Group Lung Cancer Epigenetic, Max-Planck-Institute for Heart and Lung Research, Parkstr. 1, 61231 Bad Nauheim, Germany; Universities of Giessen and Marburg Lung Center (UGMLC), Germany; German Center of Lung Research (Deutsches Zentrum für Lungenforschung, DZL), Germany. Electronic address: guillermo.barreto@mpi-bn.mpg.de.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Barreto
mesh_terms: D000818:Animals; D002460:Cell Line; D002465:Cell Movement; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004722:Endoribonucleases / Q000737:chemistry / Q000378:metabolism*; D004795:Enzyme Stability; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006868:Hydrolysis; D051379:Mice; D008958:Models, Molecular; D010766:Phosphorylation; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D016283:Proto-Oncogene Proteins p21(ras) / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020837:SOS1 Protein / Q000378:metabolism; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D013997:Time Factors; D014162:Transfection
chemical_list: D020837:SOS1 Protein; D006160:Guanosine Triphosphate; D048049:Extracellular Signal-Regulated MAP Kinases; D004722:Endoribonucleases; C022543:ribonuclease T(2); C495971:Hras protein, mouse; D016283:Proto-Oncogene Proteins p21(ras)
keywords: GAP; GEF; Guanyl-preferring RNase; KRAS; MAPK/ERK pathway; small G-proteins