2. Academic Validation
  3. TRIP12 promotes small-molecule-induced degradation through K29/K48-branched ubiquitin chains

TRIP12 promotes small-molecule-induced degradation through K29/K48-branched ubiquitin chains

  • Mol Cell. 2021 Apr 1;81(7):1411-1424.e7. doi: 10.1016/j.molcel.2021.01.023.
Ai Kaiho-Soma 1,  Yoshino Akizuki 2,  Katsuhide Igarashi 3,  Akinori Endo 4,  Takuji Shoda 5,  Yasuko Kawase 4,  Yosuke Demizu 5,  Mikihiko Naito 6,  Yasushi Saeki 4,  Keiji Tanaka 4,  Fumiaki Ohtake 7
Affiliations

Affiliations

  • 1 Institute for Advanced Life Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
  • 2 School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
  • 3 Institute for Advanced Life Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
  • 4 Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
  • 5 Division of Organic Chemistry, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki city, Kanagawa 210-9501, Japan.
  • 6 Division of Organic Chemistry, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki city, Kanagawa 210-9501, Japan; Division of Molecular Target and Gene Therapy Products, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki city, Kanagawa 210-9501, Japan.
  • 7 Institute for Advanced Life Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan. Electronic address: [email protected].
PMID: 33567268 DOI: 10.1016/j.molcel.2021.01.023
Abstract

Targeted protein degradation is an emerging therapeutic paradigm. Small-molecule degraders such as proteolysis-targeting chimeras (PROTACs) induce the degradation of neo-substrates by hijacking E3 ubiquitin ligases. Although ubiquitylation of endogenous substrates has been extensively studied, the mechanism underlying forced degradation of neo-substrates is less well understood. We found that the ubiquitin ligase TRIP12 promotes PROTAC-induced and CRL2VHL-mediated degradation of BRD4 but is dispensable for the degradation of the endogenous CRL2VHL substrate HIF-1α. TRIP12 associates with BRD4 via CRL2VHL and specifically assembles K29-linked ubiquitin chains, facilitating the formation of K29/K48-branched ubiquitin chains and accelerating the assembly of K48 linkage by CRL2VHL. Consequently, TRIP12 promotes the PROTAC-induced apoptotic response. TRIP12 also supports the efficiency of other degraders that target CRABP2 or TRIM24 or recruit CRBN. These observations define TRIP12 and K29/K48-branched ubiquitin chains as accelerators of PROTAC-directed targeted protein degradation, revealing a cooperative mechanism of branched ubiquitin chain assembly unique to the degradation of neo-substrates.

Keywords

apoptosis; cancer; cullin-RING ligase; epigenetics; targeted protein degradation; ubROTAC; ubiquitin.

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