To study protein networks containing the translation elongation factor eEF1B gamma (eEF1Bγ) in lung carcinoma cells. Methods. The protein partners of eEF1Bγ in the cytoplasmic fraction of human lung adenocarcinoma A549 cells were identified by co-immunoprecipitation (co-IP) followed by subsequent liquid chromatography-tandem mass spectrometry (LC-MS/MS). The protein interaction network for eEF1Bγ was determined by a Cytoscape 3.2.0 program using a MCODE plugin. Results. 222 high-scored proteins interacting with eEF1Bγ in the cytoplasm of A549 cells have been identified. Possible functional networks involving these protein-protein interactions were predicted using bioinformatic approaches. Conclusions. Five protein networks were identified as possible targets of eEF1Bγ in lung cancer cells. Apart from translation, eEF1Bγ was shown to be potentially involved in cell cycle regulation, nucleosome remodeling, transcription, mRNA splicing and processing, and oxidative stress response.

Aim.To study the translation elongation factor eEF1B gamma (eEF1Bγ) in the nucleus of lung carcinoma cells. Methods. The protein partners of eEF1Bγin the nuclear fraction of A549 cells were identified by co-immunoprecipitation (co-IP) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The protein interaction network for nuclear eEF1Bγ was determined by Cytoscape 3.2.0 program using the MCODE plugin. Additional analysis of the eEF1Bγ partners was conducted by Map of the cell database. Results. 234 proteins interacting with eEF1Bγ in the nuclear fraction of A549 cells were identified. Possible functional networks involving these contacts were analyzed by two bioinformatic approaches. Conclusions. Splicing of pre-mRNA and regulation of mRNA stability are assumed to be the main processes in which nuclear eEF1Bγ can be involved. We hypothesize that a portion of eEF1Bγ leaves the cytoplasmlocalizede EF1B complex during carcinogenesis and enters the nucleus to regulate certain mRNAs by affecting the splicing of their pre-mRNA and/or stability of mRNA. K e y w o r d s: eEF1Bγ, protein-protein interactions, nucleus, A549 cell Structure and Function of Biopolymers