JPOST Repositoryapplication/xmlhttps://storage.jpostdb.org/JPST004451/files/20250515_Liver.unique_genes_matrix.tsvhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_474.rawhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_454.rawhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_472.rawhttps://storage.jpostdb.org/JPST004451/files/20250509_EVO60_FAIMS_12uDIA_MEF_500ng_80.rawhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_469.rawhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_492.rawhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_467.rawhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_451.rawhttps://storage.jpostdb.org/JPST004451/files/20250509_EVO60_FAIMS_12uDIA_MEF_500ng_102.rawhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_486.rawhttps://storage.jpostdb.org/JPST004451/files/20250509_EVO60_FAIMS_12uDIA_MEF_500ng_87.rawhttps://storage.jpostdb.org/JPST004451/files/20250509_EVO60_FAIMS_12uDIA_MEF_500ng_101.rawhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_473.rawhttps://storage.jpostdb.org/JPST004451/files/20250509_EVO60_FAIMS_12uDIA_MEF_500ng_70.rawhttps://storage.jpostdb.org/JPST004451/files/20250509_EVO60_FAIMS_12uDIA_MEF_500ng_69.rawhttps://storage.jpostdb.org/JPST004451/files/20250509_EVO60_FAIMS_12uDIA_MEF_500ng_81.rawhttps://storage.jpostdb.org/JPST004451/files/20250509_EVO60_FAIMS_12uDIA_MEF_500ng_86.rawhttps://storage.jpostdb.org/JPST004451/files/20250505_EVO60_FAIMS_12uDIA_Liver_500ng_493.rawhttps://storage.jpostdb.org/JPST004451/files/20250509_EVO60_FAIMS_12uDIA_MEF_500ng_108.rawprimaryOK200ProteomicsMasaki HosoganeMus Musculus (mouse)https://repository.jpostdb.org/entry/JPST004451Dokkyo Medical UniversityjPOSTfalseWhole proteome of MEFs and liver tissue from WT and Eef1d exon 5 KO miceThe EEF1B complex plays a central role in translation elongation by reactivating EEF1A for delivery of aminoacyl-tRNAs to the ribosome. Among its components, EEF1D undergoes alternative splicing to produce one long and several short isoforms, each with distinct N-terminal domains and tissue-specific expression patterns. Although the short isoforms are broadly expressed, their functional significance has remained unclear. In this study, we show that short EEF1D isoforms containing exon 5 interact with endoplasmic reticulum (ER)-resident scaffold protein KTN1 and RRBP1, thereby anchoring the EEF1B complex to the ER. Mass spectrometry of FLAG-tagged EEF1D identified these interactions, and deletion of exon 5 disrupted ER anchoring, resulting in diffuse cytoplasmic localization of the EEF1B complex. In exon 5 knockout mice, this altered localization was accompanied by reduced EEF1B subunit abundance in multiple tissues, including liver, although global protein synthesis rates remained unaffected. These findings uncover an ER-anchoring mechanism controlled by alternative splicing that shapes the spatial organization and abundance of the elongation machinery in vivo.Sat May 30 00:00:00 GMT+01:00 2026PXD07554210090