1. ELK-1 ubiquitination status and transcriptional activity are modulated independently of F-Box protein FBXO25
- Author
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Franziska Gehringer, Peter E. Shaw, Charles Ducker, Janice Saxton, and Reyna Sara Quintero-Barceinas
- Subjects
0301 basic medicine ,Transcription, Genetic ,animal diseases ,SUMO protein ,Biochemistry ,F-box protein ,Mice ,IMAC, immobilized metal affinity chromatography ,fluids and secretions ,Ubiquitin ,UPS, ubiquitin-proteasome-system ,Basic Helix-Loop-Helix Transcription Factors ,ubiquitin-specific protease 17 (USP17) ,Phosphorylation ,Regulation of gene expression ,biology ,Chemistry ,ETS transcription factor family ,ERKs, extracellular signal-regulated kinases ,TPA, tetradecanoylphorbol acetate ,Cell cycle ,Ubiquitin ligase ,Cell biology ,DMEM, Dulbecco’s Modified Eagle’s Medium ,Plasmids ,Protein Binding ,Research Article ,MEFs, murine embryonic fibroblasts ,MRTFs, myocardin-related transcription factors ,Nerve Tissue Proteins ,Transfection ,ubiquitin ligase ,bHLH, basic helix–loop–helix protein ,Cell Line ,03 medical and health sciences ,mUBQ, monoubiquitin ,CHX, cycloheximide ,Endopeptidases ,Animals ,Humans ,Amino Acid Sequence ,Molecular Biology ,development ,Adaptor Proteins, Signal Transducing ,ets-Domain Protein Elk-1 ,030102 biochemistry & molecular biology ,Sequence Homology, Amino Acid ,F-Box Proteins ,Ubiquitination ,Sumoylation ,Cell Biology ,Fibroblasts ,CHIP, C-terminus of HSP70 interacting protein ,SRF, serum response factor ,030104 developmental biology ,HEK293 Cells ,cell proliferation ,Proteasome ,USP17, ubiquitin-specific protease 17 ,biology.protein ,FCS, fetal calf serum ,pUBQ, polyubiquitin chains ,gene regulation ,Protein Processing, Post-Translational ,Sequence Alignment ,HeLa Cells ,qRT-PCR, quantitative reverse transcription–polymerase chain reaction - Abstract
The mitogen-responsive, ETS-domain transcription factor ELK-1 stimulates the expression of immediate early genes at the onset of the cell cycle and participates in early developmental programming. ELK-1 is subject to multiple levels of posttranslational control, including phosphorylation, SUMOylation, and ubiquitination. Recently, removal of monoubiquitin from the ELK-1 ETS domain by the Ubiquitin Specific Protease USP17 was shown to augment ELK-1 transcriptional activity and promote cell proliferation. Here we have used coimmunoprecipitation experiments, protein turnover and ubiquitination assays, RNA-interference and gene expression analyses to examine the possibility that USP17 acts antagonistically with the F-box protein FBXO25, an E3 ubiquitin ligase previously shown to promote ELK-1 ubiquitination and degradation. Our data confirm that FBXO25 and ELK-1 interact in HEK293T cells and that FBXO25 is active toward Hand1 and HAX1, two of its other candidate substrates. However, our data indicate that FBXO25 neither promotes ubiquitination of ELK-1 nor impacts on its transcriptional activity and suggest that an E3 ubiquitin ligase other than FBXO25 regulates ELK-1 ubiquitination and function.
- Published
- 2021