title: Cereblon inhibits proteasome activity by binding to the 20S core proteasome subunit beta type 4.
abstract: In humans, mutations in the gene encoding cereblon (CRBN) are associated with mental retardation. Although CRBN has been investigated in several cellular contexts, its function remains unclear. Here, we demonstrate that CRBN plays a role in regulating the ubiquitin-proteasome system (UPS). Heterologous expression of CRBN inhibited proteasome activity in a human neuroblastoma cell line. Furthermore, proteasome subunit beta type 4 (PSMB4), the β7 subunit of the 20S core complex, was identified as a direct binding partner of CRBN. These findings suggest that CRBN may modulate proteasome activity by directly interacting with the β7 subunit.
authors.affiliation: School of Life Sciences and Cell Dynamics Research Center and National Leading Research Laboratory for Ion Channels, Gwangju Institute Science and Technology (GIST), Gwangju 500-712, Republic of Korea.
authors.forename: Kwang Min
authors.initials: KM
authors.lastname: Lee
authors.forename: Jongwon
authors.initials: J
authors.lastname: Lee
authors.forename: Chul-Seung
authors.initials: CS
authors.lastname: Park
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D002460:Cell Line; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000378:metabolism; D015536:Down-Regulation; D057809:HEK293 Cells; D006801:Humans; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C502543:CRBN protein, human; D044767:Ubiquitin-Protein Ligases; D010447:Peptide Hydrolases; D002918:Chymotrypsin; C108898:PSMB4 protein, human; D046988:Proteasome Endopeptidase Complex