Abstract
Hypoxic growth of fungi requires sterol regulatory element-binding protein (SREBP) transcription factors, and human opportunistic fungal pathogens require SREBP activation for virulence. Proteolytic release of fission yeast SREBPs from the membrane in response to low oxygen requires the Golgi membrane-anchored Dsc E3 ligase complex. Using genetic interaction arrays, we identified Rbd2 as a rhomboid family protease required for SREBP proteolytic processing. Rbd2 is an active, Golgi-localized protease that cleaves the transmembrane segment of the TatA rhomboid model substrate. Epistasis analysis revealed that the Dsc E3 ligase acts on SREBP prior to cleavage by Rbd2. Using APEX2 proximity biotinylation, we demonstrated that Rbd2 binds the AAA-ATPase Cdc48 through a C-terminal SHP box. Interestingly, SREBP cleavage required Rbd2 binding of Cdc48, consistent with Cdc48 acting to recruit ubiquitinylated substrates. In support of this claim, overexpressing a Cdc48-binding mutant of Rbd2 bypassed the Cdc48 requirement for SREBP cleavage, demonstrating that Cdc48 likely plays a role in SREBP recognition. In the absence of functional Rbd2, SREBP precursor is degraded by the proteasome, indicating that Rbd2 activity controls the balance between SREBP activation and degradation.
| Original language | English (US) |
|---|---|
| Journal | EMBO Journal |
| DOIs | |
| State | Accepted/In press - 2016 |
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Keywords
- SREBP
- Cdc48/p97
- Intramembrane proteolysis
- Rhomboid
- Ubiquitin
ASJC Scopus subject areas
- Neuroscience(all)
- Molecular Biology
- Immunology and Microbiology(all)
- Biochemistry, Genetics and Molecular Biology(all)
Cite this
A Golgi rhomboid protease Rbd2 recruits Cdc48 to cleave yeast SREBP. / Hwang, Jiwon; Ribbens, Diedre; Raychaudhuri, Sumana; Cairns, Leah; Gu, He; Frost, Adam; Urban, Sinisa; Espenshade, Peter.
In: EMBO Journal, 2016.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A Golgi rhomboid protease Rbd2 recruits Cdc48 to cleave yeast SREBP
AU - Hwang, Jiwon
AU - Ribbens, Diedre
AU - Raychaudhuri, Sumana
AU - Cairns, Leah
AU - Gu, He
AU - Frost, Adam
AU - Urban, Sinisa
AU - Espenshade, Peter
PY - 2016
Y1 - 2016
N2 - Hypoxic growth of fungi requires sterol regulatory element-binding protein (SREBP) transcription factors, and human opportunistic fungal pathogens require SREBP activation for virulence. Proteolytic release of fission yeast SREBPs from the membrane in response to low oxygen requires the Golgi membrane-anchored Dsc E3 ligase complex. Using genetic interaction arrays, we identified Rbd2 as a rhomboid family protease required for SREBP proteolytic processing. Rbd2 is an active, Golgi-localized protease that cleaves the transmembrane segment of the TatA rhomboid model substrate. Epistasis analysis revealed that the Dsc E3 ligase acts on SREBP prior to cleavage by Rbd2. Using APEX2 proximity biotinylation, we demonstrated that Rbd2 binds the AAA-ATPase Cdc48 through a C-terminal SHP box. Interestingly, SREBP cleavage required Rbd2 binding of Cdc48, consistent with Cdc48 acting to recruit ubiquitinylated substrates. In support of this claim, overexpressing a Cdc48-binding mutant of Rbd2 bypassed the Cdc48 requirement for SREBP cleavage, demonstrating that Cdc48 likely plays a role in SREBP recognition. In the absence of functional Rbd2, SREBP precursor is degraded by the proteasome, indicating that Rbd2 activity controls the balance between SREBP activation and degradation.
AB - Hypoxic growth of fungi requires sterol regulatory element-binding protein (SREBP) transcription factors, and human opportunistic fungal pathogens require SREBP activation for virulence. Proteolytic release of fission yeast SREBPs from the membrane in response to low oxygen requires the Golgi membrane-anchored Dsc E3 ligase complex. Using genetic interaction arrays, we identified Rbd2 as a rhomboid family protease required for SREBP proteolytic processing. Rbd2 is an active, Golgi-localized protease that cleaves the transmembrane segment of the TatA rhomboid model substrate. Epistasis analysis revealed that the Dsc E3 ligase acts on SREBP prior to cleavage by Rbd2. Using APEX2 proximity biotinylation, we demonstrated that Rbd2 binds the AAA-ATPase Cdc48 through a C-terminal SHP box. Interestingly, SREBP cleavage required Rbd2 binding of Cdc48, consistent with Cdc48 acting to recruit ubiquitinylated substrates. In support of this claim, overexpressing a Cdc48-binding mutant of Rbd2 bypassed the Cdc48 requirement for SREBP cleavage, demonstrating that Cdc48 likely plays a role in SREBP recognition. In the absence of functional Rbd2, SREBP precursor is degraded by the proteasome, indicating that Rbd2 activity controls the balance between SREBP activation and degradation.
KW - SREBP
KW - Cdc48/p97
KW - Intramembrane proteolysis
KW - Rhomboid
KW - Ubiquitin
UR - http://www.scopus.com/inward/record.url?scp=84988369511&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84988369511&partnerID=8YFLogxK
U2 - 10.15252/embj.201693923
DO - 10.15252/embj.201693923
M3 - Article
C2 - 27655872
AN - SCOPUS:84988369511
JO - EMBO Journal
JF - EMBO Journal
SN - 0261-4189
ER -