Open AccessDepletion of eukaryotic initiation factor 5B (eIF5B) reprograms the cellular transcriptome and leads to activation of endoplasmic reticulum (ER) stress and c-Jun N-terminal kinase (JNK)
Author(s) -
Kamiko R. Bressler,
Joseph A. Ross,
Slava Ilnytskyy,
Keiran Vanden Dungen,
Katrina Taylor,
Krishna Patel,
Athanasios Zovoilis,
Igor Kovalchuk,
Nehal Thakor
Publication year - 2021
Publication title -
cell stress and chaperones
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.994
H-Index - 87
eISSN - 1466-1268
pISSN - 1355-8145
DOI - 10.1007/s12192-020-01174-1
Subject(s) - internal ribosome entry site , microbiology and biotechnology , eukaryotic initiation factor , atf4 , integrated stress response , unfolded protein response , biology , endoplasmic reticulum , upstream open reading frame , translational regulation , eif 2 kinase , downregulation and upregulation , translation (biology) , kinase , protein kinase a , messenger rna , biochemistry , cyclin dependent kinase 2 , gene
During the integrated stress response (ISR), global translation initiation is attenuated; however, noncanonical mechanisms allow for the continued translation of specific transcripts. Eukaryotic initiation factor 5B (eIF5B) has been shown to play a critical role in canonical translation as well as in noncanonical mechanisms involving internal ribosome entry site (IRES) and upstream open reading frame (uORF) elements. The uORF-mediated translation regulation of activating transcription factor 4 (ATF4) mRNA plays a pivotal role in the cellular ISR. Our recent study confirmed that eIF5B depletion removes uORF2-mediated repression of ATF4 translation, which results in the upregulation of growth arrest and DNA damage-inducible protein 34 (GADD34) transcription. Accordingly, we hypothesized that eIF5B depletion may reprogram the transcriptome profile of the cell. Here, we employed genome-wide transcriptional analysis on eIF5B-depleted cells. Further, we validate the up- and downregulation of several transcripts from our RNA-seq data using RT-qPCR. We identified upregulated pathways including cellular response to endoplasmic reticulum (ER) stress, and mucin-type O-glycan biosynthesis, as well as downregulated pathways of transcriptional misregulation in cancer and T cell receptor signaling. We also confirm that depletion of eIF5B leads to activation of the c-Jun N-terminal kinase (JNK) arm of the mitogen-activated protein kinase (MAPK) pathway. This data suggests that depletion of eIF5B reprograms the cellular transcriptome and influences critical cellular processes such as ER stress and ISR.