Small-molecule inhibitors of linear ubiquitin chain assembly complex (LUBAC), HOIPINs, suppress NF-κB signaling

K Katsuya, D Oikawa, K Iio, S Obika, Y Hori… - Biochemical and …, 2019 - Elsevier
K Katsuya, D Oikawa, K Iio, S Obika, Y Hori, T Urashima, K Ayukawa, F Tokunaga
Biochemical and biophysical research communications, 2019Elsevier
Nuclear factor-κB (NF-κB) is a crucial transcription factor family involved in the regulation of
immune and inflammatory responses and cell survival. The linear ubiquitin chain assembly
complex (LUBAC), composed of the HOIL-1L, HOIP, and SHARPIN subunits, specifically
generates Met1-linked linear ubiquitin chains through the ubiquitin ligase activity in HOIP,
and activates the NF-κB pathway. We recently identified a chemical inhibitor of LUBAC,
which we named HOIPIN-1 (HOIP inhibitor-1). To improve the potency of HOIPIN-1, we …
Abstract
Nuclear factor-κB (NF-κB) is a crucial transcription factor family involved in the regulation of immune and inflammatory responses and cell survival. The linear ubiquitin chain assembly complex (LUBAC), composed of the HOIL-1L, HOIP, and SHARPIN subunits, specifically generates Met1-linked linear ubiquitin chains through the ubiquitin ligase activity in HOIP, and activates the NF-κB pathway. We recently identified a chemical inhibitor of LUBAC, which we named HOIPIN-1 (HOIP inhibitor-1). To improve the potency of HOIPIN-1, we synthesized 7 derivatives (HOIPIN-2∼8), and analyzed their effects on LUBAC and NF-κB activation. Among them, HOIPIN-8 suppressed the linear ubiquitination activity by recombinant LUBAC at an IC50 value of 11 nM, corresponding to a 255-fold increase over that of HOIPIN-1. Furthermore, as compared with HOIPIN-1, HOIPIN-8 showed 10-fold and 4-fold enhanced inhibitory activities on LUBAC- and TNF-α-induced NF-κB activation respectively, without cytotoxicity. These results indicated that HOIPIN-8 is a powerful tool to explore the physiological functions of LUBAC.
Elsevier