SIBCB scientists find novel modulator of the Hippo pathway

Researchers led by Prof. ZHANG Lei and Prof. ZHAO Yun at the Institute of Biochemistry & Cell Biology, Shanghai institutes for Biological Sciences of Chinese Academy of Sciences have identified a novel Hippo signaling component SdBP/Tgi. They identified a novel protein Sd-binding-Protein (SdBP)/Tgi, which directly competes with Yki for binding to Sd through its TDU domains and inhibits the Sd-Yki transcriptional activity to restrict growth. Their work entitled “A novel partner of Scalloped regulates Hippo signaling via antagonizing Scalloped-Yorkie activity” was published in Cell Research online on September, 2013.

The Hippo pathway controls organ growth by controlling the cell number in that organ through the inhibition of the transcriptional coactivator Yorkie by a series of phosphorylation events. It is highly conserved from Drosophila to mammals. Dysfunction of the Hippo pathway could induce diseases including tumorigenesis and cancers. To gain understanding of Hippo signaling, PhD. student GUO Tong, lab staff LU Yi and their colleagues identified a novel regulator of the Hippo pathway under the supervision of Prof. ZHANG Lei and Prof. ZHAO Yun. Using yeast two hybrid and immuopreciption, they found that SdBP (Gene no. CG10741) physically interacts with Yorkie and Scalloped via its PPXY motifs and TDU domains and inhibits growth. They also demonstrated that SdBP competes with Yki for binding to Sd through its TDU domains, resulting in negative regulation of the transcriptional activity of Sd-Yki.

This work is supported by grants from the National Basic Research Program of China, the National Natural Science Foundation of China, and the “Strategic Priority Research Program” of the Chinese Academy of Sciences.