The multi-pass transmembrane protein ACCELERATED CELL DEATH 6 (ACD6) is an immune regulator in Arabidopsis thaliana with an unclear biochemical mode of action. We have identified two loci, MODULATOR OF HYPERACTIVE ACD6 1 (MHA1) and its paralog MHA1-LIKE (MHA1L), that code for ∼7 kDa proteins, which differentially interact with specific ACD6 variants. MHA1L enhances the accumulation of an ACD6 complex, thereby increasing the activity of the ACD6 standard allele for regulating plant growth and defenses. The intracellular ankyrin repeats of ACD6 are structurally similar to those found in mammalian ion channels. Several lines of evidence link increased ACD6 activity to enhanced calcium influx, with MHA1L as a direct regulator of ACD6, indicating that peptide-regulated ion channels are not restricted to animals.

多次跨膜蛋白加速细胞死亡 6 (ACD6) 是拟南芥中的一种免疫调节剂，其生化作用模式尚不清楚。我们已经确定了两个基因座，即过度活跃 ACD6 调节因子 1 ( MHA1 ) 及其旁系同源物MHA1-LIKE ( MHA1L )，它们编码~7 kDa 蛋白，与特定 ACD6 变体存在差异性相互作用。 MHA1L 增强 ACD6 复合物的积累，从而增加 ACD6 标准等位基因调节植物生长和防御的活性。 ACD6 的细胞内锚蛋白重复序列​​在结构上与哺乳动物离子通道中的锚蛋白重复序列​​相似。多项证据将 ACD6 活性增加与钙内流增强联系起来，其中 MHA1L 作为 ACD6 的直接调节剂，表明肽调节的离子通道并不局限于动物。