HYL1-CLEAVAGE SUBTILASE 1 (HCS1) suppresses miRNA biogenesis in response to light-to-dark transition
Hyun Ju Jung, Sukwon Choi, Kyung-Hwan Boo, Jee‐Eun Kim, Young Kyoung Oh, Min Han, Moon Young Ryu, Chang Woo Lee, Christian Møller, Pratik Shah, Gu Min Kim, Woorim Yang, Seok Keun Cho, Seong Wook Yang
Abstract
mutant that is insensitive to the proteolytic activity of HCS1, confirming the importance of HCS1 in HYL1 proteostasis. Moreover, HCS1-activity is regulated by light/dark transition. Under light, cytoplasmic CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) E3 ligase suppresses HCS1-activity. COP1 sterically inhibits HCS1 by obstructing HYL1 access into the catalytic sites of HCS1. In contrast, darkness unshackles HCS1-activity for HYL1-destabilization due to nuclear COP1 relocation. Overall, the COP1-HYL1-HCS1 network may integrate two essential cellular pathways: the miRNA-biogenetic pathway and light signaling pathway.