Fig. 9: The UBC32-RED pair defines a function branch of the endoplasmic reticulum associated degradation (ERAD) pathway involved in turnover of ethylene receptors.

In the absence of ethylene, the active ETRs interact with CTR1, suppressing the ethylene signaling pathway; ethylene could cause disassociation of CTR1 and ETRs and the released CTR1 will initiate ethylene signaling. The ethylene-bound receptors were recognized by UBC32-RED module and then degraded via ERAD. Meanwhile, activation of ethylene signaling resulted in elevation of ETRs expression and de novo synthesis of active receptors, replacing the degraded ethylene-bound receptors.