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Tryptophan-mediated interactions between tristetraprolin and the CNOT9 subunit are required for CCR4-NOT deadenylase complex recruitment
- Source :
- Journal of Molecular Biology. 430(5)
- Publication Year :
- 2017
-
Abstract
- The zinc-finger protein tristetraprolin (TTP) binds to AU-rich elements present in the 3' untranslated regions of transcripts that mainly encode proteins of the inflammatory response. TTP-bound mRNAs are targeted for destruction via recruitment of the eight-subunit deadenylase complex "carbon catabolite repressor protein 4 (CCR4)-negative on TATA-less (NOT)," which catalyzes the removal of mRNA poly-(A) tails, the first obligatory step in mRNA decay. Here we show that a novel interaction between TTP and the CCR4-NOT subunit, CNOT9, is required for recruitment of the deadenylase complex. In addition to CNOT1, CNOT9 is now included in the identified CCR4-NOT subunits shown to interact with TTP. We find that both the N- and C-terminal domains of TTP are involved in an interaction with CNOT9. Through a combination of SPOT peptide array, site-directed mutagenesis, and bio-layer interferometry, we identified several conserved tryptophan residues in TTP that serve as major sites of interaction with two tryptophan-binding pockets of CNOT9, previously found to interact with another modulator GW182. We further demonstrate that these interactions are also required for recruitment of the CCR4-NOT complex and TTP-directed decay of an mRNA containing an AU-rich element in its 3'-untranslated region. Together the results reveal new molecular details for the TTP-CNOT interaction that shape an emerging mechanism whereby TTP targets inflammatory mRNAs for deadenylation and decay.
- Subjects :
- 0301 basic medicine
Untranslated region
Receptors, CCR4
RNA Stability
Protein subunit
Tristetraprolin
Catabolite repression
Repressor
Autoantigens
03 medical and health sciences
Structural Biology
hemic and lymphatic diseases
Humans
Protein Interaction Domains and Motifs
RNA, Messenger
3' Untranslated Regions
Molecular Biology
AU-rich element
Messenger RNA
030102 biochemistry & molecular biology
Chemistry
Mutagenesis
Tryptophan
RNA-Binding Proteins
respiratory system
Cell biology
030104 developmental biology
Exoribonucleases
Mutagenesis, Site-Directed
HeLa Cells
Transcription Factors
Subjects
Details
- Language :
- English
- ISSN :
- 00222836
- Volume :
- 430
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- Journal of Molecular Biology
- Accession number :
- edsair.doi.dedup.....d32cfce30dae4530a53ae8f1a3cde720