Ubiquitin ligases

  • Article |

    Polycomb repressive complex 1 (PRC1) ubiquitinates histone H2A at lysine 119. Here the authors show that the intrinsically low activity of PCGF4–RING1B, a canonical PRC1 E3 ligase, is offset by a favourable interaction with nucleosome substrates, resulting in efficient site-specific monoubiquitination.

    • Asad M. Taherbhoy
    • , Oscar W. Huang
    •  & Andrea G. Cochran
  • Article
    | Open Access

    The SUMO-targeted ubiquitin ligase RNF111 promotes K63-linked ubiquitylation of SUMOylated XPC after DNA damage. Here the authors show that RNF111 is responsible for sequential XPC ubiquitylation, and RNF111-mediated ubiquitylation promotes the release of XPC from damaged DNA after NER initiation.

    • Loes van Cuijk
    • , Gijsbert J. van Belle
    •  & Jurgen A. Marteijn
  • Article |

    Phosphorylation of insulin receptor substrate (IRS)-1/2 by insulin-like growth factor (IGF)-I receptor tyrosine kinase is essential for IGF signalling. Here, the authors show that monoubiquitination of IRS-2 by the ubiquitin ligase Nedd4 recruits IRS-2 to the cell membrane and increases IRS-2 phosphorylation and IGF signalling.

    • Toshiaki Fukushima
    • , Hidehito Yoshihara
    •  & Shin-Ichiro Takahashi
  • Article |

    Ras signalling activates the transcription factor c-Jun/AP-1, but the mechanism was unclear. Here, Chakraborty et al.describe a phosphorylation–ubiquitination cascade involving MSK1 and the E3 ubiquitin ligases Trim7 and RACO-1, which mediates c-Jun activation in Ras-driven lung tumorigenesis.

    • Atanu Chakraborty
    • , Markus E. Diefenbacher
    •  & Axel Behrens
  • Article |

    The Hippo pathway plays a role in regulating organ size and stem cell renewal but the regulatory mechanisms that fine-tune this pathway are not well understood. Here the authors report on the role of NEDD4 as a negative regulator of the Hippo signalling components, WW45 and LATS kinase, and in controlling cell proliferation and intestinal stem cell homeostasis.

    • Sung Jun Bae
    • , Myungjin Kim
    •  & Jae Hong Seol
  • Article
    | Open Access

    SUMO forms flexible polymeric chains that can interact with ubiquitin ligases, such as RNF4. Here Xu et al. have used NMR spectroscopy and biochemical experiments to investigate the interaction between SUMO and RNF4, and propose a mechanism for delivery of substrates to the ubiquitination machinery.

    • Yingqi Xu
    • , Anna Plechanovová
    •  & Steve J. Matthews
  • Article
    | Open Access

    The human cytomegalovirus protein US11 downregulates host immune responses by redirecting HLA class I molecules for endoplasmic reticulum-associated protein degradation. Using a high-coverage genome-wide shRNA screen, the authors identify TMEM129 as an E3 ubiquitin ligase essential for this process.

    • Michael L. van de Weijer
    • , Michael C. Bassik
    •  & Robert Jan Lebbink
  • Article |

    The E3 ubiquitin ligase APC/C plays a critical role in cell cycle progression. In this study, Delgado-Esteban et al. show that APC/C bound to the co-factor Cdh1 is necessary for neural progenitor cell maintenance and neuronal differentiation.

    • Maria Delgado-Esteban
    • , Irene García-Higuera
    •  & Angeles Almeida
  • Article |

    Pellino family proteins are ubiquitin ligases known to regulate immune signalling. Here Yang et al. show that Pellino3 regulates apoptotic TNF signalling by modulating the composition of the death-induced signalling complex, and that absence of Pellino3 sensitizes mice to TNF.

    • Shuo Yang
    • , Bingwei Wang
    •  & Paul N. Moynagh
  • Article
    | Open Access

    CAND1 promotes the activity of Cullin–RING ubiquitin ligases, but binds exclusively to inactive unneddylated forms of the enzyme. By identifying a simple means to reversibly activate this complex in budding yeast, Zemla et al. resolve this paradox and show that CAND1 acts as an exchange factor for substrate adaptors.

    • Aleksandra Zemla
    • , Yann Thomas
    •  & Thimo Kurz
  • Article |

    Cullin 1-RING ubiquitin ligase complexes interact with a wide variety of substrates by recruiting different substrate receptor subunits. Here the authors demonstrate that CAND1 promotes rapid exchange of substrate receptors, thus ensuring comprehensive sampling of the entire repertoire.

    • Shuangding Wu
    • , Wenhong Zhu
    •  & Dieter A. Wolf
  • Article |

    The proapoptotic protein Siva1 has been shown to inhibit the tumour suppressor p53, however, it remains unclear how this activity is mediated. Here the authors show that Siva1 is an E3 ubiquitin ligase which inhibits p53 by promoting the degradation of ARF.

    • Xingwu Wang
    • , Meng Zha
    •  & Mian Wu
  • Article |

    NFκB/p65 and PPARγ are both transcription factors that perform distinct but overlapping roles in cellular regulation. Hou et al. report that PPARγ acts as an E3 ubiquitin ligase and promotes Lys48-linked ubiquitination and degradation of p65, terminating NFκB-mediated inflammation and tumorigenesis.

    • Yongzhong Hou
    • , France Moreau
    •  & Kris Chadee
  • Article
    | Open Access

    Fbw7 is a ubiquitin-ligase, which targets several oncoproteins for proteolysis, and is therefore important for the control and prevention of tumorigenesis. In this study, Arabi and colleagues carry out a proteomic screen of the targets of Fbw7, and identify Nuclear Factor of κ-B2 as a substrate.

    • Azadeh Arabi
    • , Karim Ullah
    •  & Olle Sangfelt
  • Article |

    The Golgi membrane is fragmented during mitosis and is subsequently fused following cell division and this process is known to be controlled by ubiquitination. In this study, the ubiquitin ligase HACE1 is shown to be targeted to the Golgi membrane and is required for fusion after the completion of mitosis.

    • Danming Tang
    • , Yi Xiang
    •  & Yanzhuang Wang
  • Article |

    Transforming growth factor-β blocks the activation of pro-inflammatory cytokines, in part by the degradation of Myd88. This study shows that smad ubiquitin regulator proteins are shown to mediate the destruction of Myd8 and are therefore required for the anti-inflammatory effects of transforming growth factor-β.

    • Youn Sook Lee
    • , Jin Seok Park
    •  & Seok Hee Park
  • Article
    | Open Access

    In vitrostudies have suggested that the ubiquitin ligase, Nedd4-2, regulates several proteins, including the epithelial sodium channel. Here by examining Nedd4-2-deficient mice, the authors demonstrate that Nedd4-2 is essential for epithelial sodium channel regulation, fetal and postnatal lung function and animal survival.

    • Natasha A. Boase
    • , Grigori Y. Rychkov
    •  & Sharad Kumar