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The TFIIH subunit Tfb3 regulates cullin neddylation
Gwenaël Rabut1, Gaëlle Le Dez, Rati Verma
1Institute of Biochemistry, ETH Zurich, Zurich, Switzerland. gwenael.rabut@univ-rennes1.fr
Molecular Cell
|August 6, 2011
Summary
The study reveals that yeast Rtt101 (a cullin protein) undergoes both neddylation and ubiquitylation, crucial for its function. The protein Tfb3 regulates these modifications and cullin activation.
Area of Science:
- Cellular Biology
- Protein Modification
- Ubiquitin Ligase Regulation
Background:
- Cullin proteins are essential scaffolds for ubiquitin ligases, regulating diverse cellular functions.
- Cullin activity is controlled by mechanisms including neddylation of their C-terminal domain.
Purpose of the Study:
- To investigate the modifications and regulation of the yeast Cul4-type cullin, Rtt101.
- To identify factors involved in Rtt101 neddylation and ubiquitylation and their impact on function.
Main Methods:
- Yeast genetics and molecular biology techniques.
- Analysis of protein modification (neddylation and ubiquitylation) in vivo.
- Protein interaction studies.
Main Results:
- Yeast Rtt101 is both neddylated and ubiquitylated, with both modifications promoting its function.
- Rtt101 ubiquitylation depends on Ubc4; neddylation involves Tfb3, a subunit of transcription factor TFIIH.
- Tfb3 also regulates Cul3 neddylation and activity, interacting with key components of the cullin modification machinery.
Conclusions:
- The conserved RING domain protein Tfb3 plays a critical role in controlling the activation of a subset of cullins.
- Distinct ubiquitin-conjugating enzymes and specific factors like Tfb3 mediate Rtt101 modification and function.
- This study uncovers novel regulatory pathways for cullin proteins involving Tfb3.
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