WUSCHEL-Responsive At5g65480 Interacts with CLAVATA Components In Vitro and in Transient Expression

The CLAVATA (CLV) signaling pathway is essential for shoot meristem homeostasis in Arabidopsis. CLV acts to limit the expression domain of the stem cell-promoting gene WUSCHEL (WUS). The closely related receptor-kinases CLV1 and BAM1 are key components in this pathway; however, the downstream factors that link the receptors to WUS regulation are poorly understood. The Arabidopsis gene At5g65480 was recently identified as a direct transcriptional target up-regulated by WUS. We have independently identified this gene which we term CCI1 as a CLV1 and BAM1 interacting protein in vitro and in transient expression. CCI1 has phosphatidylinositide-binding activity in vitro and localizes to the plasma membrane in transient expression. Furthermore, CLV signaling components and CCI1 both partition to detergent-resistant membrane microdomains characterized as lipid rafts.CLAVATA（CLV）信号通路对于拟南芥的茎尖分生组织稳态至关重要。CLV通过限制促进干细胞的基因WUSCHEL（WUS）的表达域来发挥调控功能。紧密相关的受体激酶CLV1与BAM1是该通路的核心组分；然而，连接该类受体与WUS调控过程的下游因子仍未得到充分解析。近期研究将拟南芥基因At5g65480鉴定为受WUS正向调控的直接转录靶标。我们独立鉴定出该基因，并将其命名为CCI1，该蛋白在体外与瞬时表达体系中均可与CLV1和BAM1发生相互作用。CCI1在体外具备磷脂酰肌醇结合活性，且在瞬时表达实验中定位于质膜。此外，CLV信号通路组分与CCI1均富集于被定义为脂筏的去污剂抗性膜微结构域中。