Habisov Sabrina, Huber Jessica, Ichimura Yoshinobu, Akutsu Masato, Rogova Natalia, Loehr Frank, McEwan David G, Johansen Terje, Dikic Ivan, Doetsch Volker, Komatsu Masaaki, Rogov Vladimir V, Kirkin Vladimir
From Translational Innovation Platform Oncology, Merck KGaA, Frankfurter Strasse 250, 64293 Darmstadt, Germany, the Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany, the BMLS Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Riedberg Campus, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany.
the Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main, Germany.
J Biol Chem. 2016 Apr 22;291(17):9025-41. doi: 10.1074/jbc.M116.715474. Epub 2016 Feb 29.
The covalent conjugation of ubiquitin-fold modifier 1 (UFM1) to proteins generates a signal that regulates transcription, response to cell stress, and differentiation. Ufmylation is initiated by ubiquitin-like modifier activating enzyme 5 (UBA5), which activates and transfers UFM1 to ubiquitin-fold modifier-conjugating enzyme 1 (UFC1). The details of the interaction between UFM1 and UBA5 required for UFM1 activation and its downstream transfer are however unclear. In this study, we described and characterized a combined linear LC3-interacting region/UFM1-interacting motif (LIR/UFIM) within the C terminus of UBA5. This single motif ensures that UBA5 binds both UFM1 and light chain 3/γ-aminobutyric acid receptor-associated proteins (LC3/GABARAP), two ubiquitin (Ub)-like proteins. We demonstrated that LIR/UFIM is required for the full biological activity of UBA5 and for the effective transfer of UFM1 onto UFC1 and a downstream protein substrate both in vitro and in cells. Taken together, our study provides important structural and functional insights into the interaction between UBA5 and Ub-like modifiers, improving the understanding of the biology of the ufmylation pathway.
泛素折叠修饰因子1（UFM1）与蛋白质的共价结合产生一种信号，该信号可调节转录、细胞应激反应和分化。Ufmylation由泛素样修饰激活酶5（UBA5）启动，UBA5激活并将UFM1转移至泛素折叠修饰结合酶1（UFC1）。然而，UFM1激活及其下游转移所需的UFM1与UBA5之间相互作用的细节尚不清楚。在本研究中，我们描述并鉴定了UBA5 C末端内的一个组合线性LC3相互作用区域/UFM1相互作用基序（LIR/UFIM）。这个单一基序确保UBA5结合UFM1和轻链3/γ-氨基丁酸受体相关蛋白（LC3/GABARAP）这两种类泛素（Ub）蛋白。我们证明，LIR/UFIM对于UBA5的完全生物学活性以及UFM1在体外和细胞内有效转移至UFC1和下游蛋白质底物都是必需的。综上所述，我们的研究为UBA5与类泛素修饰因子之间的相互作用提供了重要的结构和功能见解，增进了对Ufmylation途径生物学的理解。
