A team of scientists led by Prof. ZHAO Yun at the Institute of Biochemistry and Cell Biology (SIBCB), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, have identified a novel role for SUMO in maintaining CySCs in adult Drosophila testis. 

Post-translational modifications (PTMs) regulate diverse cellular processes, including transcription, replication, and DNA repair. SUMOylation is an ubiquitin-like PTM. Disruption of SUMO pathway during embryogenesis leads to lethality from Drosophila to mouse. However, the function of SUMOylation in adults, especially in stem cell maintenance, is largely unknown. 

Supervised by Prof. ZHAO Yun, LV Xiangdong, PAN Chenyu and colleagues identified the novel function of SUMOylation in CySCs self-renewal in adult Drosophila testis. Reduction of SUMOylation promotes premature differentiation of CySCs and impedes the proliferation of CySCs, which finally reduce the number of CySCs. Moreover, inhibition of SUMO pathway phenocopies the disruption of Hedgehog (Hh) pathway, and can block the promoted proliferation of CySCs by Hh activation. Importantly, SUMO pathway directly regulates the SUMOylation of Hh pathway transcriptional factor, Cubitus interruptus (Ci), which is required for promoting CySCs proliferation. In all, this study revealed that SUMO directly targets Hh pathway and regulates CySCs maintenance in adult Drosophila testis. 

This study entitled “SUMO Regulates Somatic Cyst Stem Cells Maintenance and Directly Targets Hedgehog Pathway in Adult Drosophila Testis” was published online by Development on 24 March, 2016. 

This work was supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences and the National Natural Science Foundation of China. 

The SUMO pathway directly targets Hh pathway and cell-autonomously regulates CySCs maintenance in adult Drosophila testis. (Image by ZHAO Yun’s group)