USP11 deubiquitinates monoubiquitinated SPRTN to repair DNA-protein crosslinks

ABSTRACT: DNA-protein crosslinks (DPCs) are toxic DNA lesions that interfere with DNA metabolic processes such as replication, transcription, and recombination. SPRTN is a replication-coupled DNA-dependent metalloprotease that degrades proteins crosslinked to DNA to promote DPC repair. SPRTN function is tightly regulated by a monoubiquitin switch that controls SPRTN chromatin accessibility during DPC repair. The deubiquitinase regulating SPRTN function in DPC repair is unknown. To identify SPRTN modifiers, we performed tandem-affinity purification and mass spectrometry (TAP-MS) analysis of SFB (S-FLAG-streptavidin binding peptide)-tagged SPRTN expressed in HEK 293T cells. We screened the MS list for proteins that are known to function as a deubiquitinase and identified only one potential SPRTN modifier, USP11 deubiquitinase. A reciprocal TAP-MS analysis of SFB-USP11 expressed in HEK 293T cells treated with camptothecin (CPT) immunoprecipitated SPRTN. USP11 interacts with SPRTN and cleaves monoubiquitinated SPRTN in cells and in vitro. USP11 depletion impaired SPRTN deubiquitination in response to formaldehyde-induced DPCs. Loss of USP11 causes an accumulation of unrepaired DPCs and cellular hypersensitivity to treatment with DPC-inducing agents. Our findings elucidates the function of USP11 in the regulation of SPRTN monoubiquitination and SPRTN-mediated DPC repair.

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture, Hek-293t/17 Cell

SUBMITTER: Gargi Ghosal  

LAB HEAD: Gargi Ghosal

PROVIDER: PXD019923 | Pride | 2021-04-01

REPOSITORIES: Pride