RRC ID 81372
Author Tsunoda T, Riku M, Yamada N, Tsuchiya H, Tomita T, Suzuki M, Kizuki M, Inoko A, Ito H, Murotani K, Murakami H, Saeki Y, Kasai K.
Title ENTREP/FAM189A2 encodes a new ITCH ubiquitin ligase activator that is downregulated in breast cancer.
Journal EMBO Rep
Abstract The HECT-type ubiquitin E3 ligases including ITCH regulate many aspects of cellular function through ubiquitinating various substrates. These ligases are known to be allosterically autoinhibited and to require an activator protein to fully achieve the ubiquitination of their substrates. Here we demonstrate that FAM189A2, a downregulated gene in breast cancer, encodes a new type of ITCH activator. FAM189A2 is a transmembrane protein harboring PPxY motifs, and the motifs mediate its association with and ubiquitination by ITCH. FAM189A2 also associates with Epsin and accumulates in early and late endosomes along with ITCH. Intriguingly, FAM189A2 facilitates the association of a chemokine receptor CXCR4 with ITCH and enhances ITCH-mediated ubiquitination of CXCR4. FAM189A2-knockout prohibits CXCL12-induced endocytosis of CXCR4, thereby enhancing the effects of CXCL12 on the chemotaxis and mammosphere formation of breast cancer cells. In comparison to other activators or adaptors known in the previous studies, FAM189A2 is a unique activator for ITCH to desensitize CXCR4 activity, and we here propose that FAM189A2 be renamed as ENdosomal TRansmembrane binding with EPsin (ENTREP).
Volume 23(2)
Pages e51182
Published 2022-2-3
DOI 10.15252/embr.202051182
PMID 34927784
PMC PMC8811627
MeSH Breast Neoplasms* / genetics Chemokine CXCL12 Female Gene Knockout Techniques Humans Receptors, CXCR4 Repressor Proteins* / genetics Repressor Proteins* / metabolism Ubiquitin-Protein Ligases* / genetics Ubiquitin-Protein Ligases* / metabolism Ubiquitination
Resource
DNA material CSII-CMV-MCS-IRES2-Bsd (RDB04385) pCMV-VSV-G-RSV-Rev (RDB04393) pCAG-HIVgp (RDB04394)