xbp1 activation

Toyocamycin (Vengicide) is an adenosine analog produced by Actinomycetes, functioning as an XBP1 inhibitor and inhibiting IRE1α-induced ATP-dependent XBP1 mRNA cleavage (IC50: 80 nM), and induces apoptosis.

AK177 is an allosteric activator of IRE1α ribonuclease, exhibiting binding affinities of 480 nM for non-phosphorylated and 180 nM for phosphorylated IRE1α. It promotes concentration-dependent cleavage of XBP1 mRNA probes by IRE1α and stably binds its kinase domain. However, AK177 displays poor kinase selectivity, and due to inadequate membrane permeability, shows negligible downstream pathway activation and antiproliferative activity at the cellular level.