Dr. Yajuan Li’s new paper accepted
Dr. Yajuan Li’s new paper titled with “Functional and Structural Characterization of Zebrafish ASC” was accepted by FEBS journal on May 12nd, many congratulations! Dr. Li started her postdoctoral training in TJ-lab since May 2015. In the past three years, she has published two research articles and one review paper. She also obtained several research grants including the China Postdoctoral Science Foundation (Grant No.: 2015M582007), the National Natural Science Fund for Young Scholars (Grant No.: 31600598), and the Tenth Batch Special Support of China Postdoctoral Science Foundation (Grant No.: 2015T100454). She will start her independent research career after leaving TJ-lab in May 2018.
The zebrafish genome encodes homologs for most of the proteins involved in inflammatory pathways; however, the molecular components and activation mechanisms of fish inflammasomes are largely unknown. ASC (apoptosis-associated speck-like protein containing a caspase-recruitment domain (CARD)) is the only adaptor involved in the formation of multiple types of inflammasomes. Here, we demonstrate that zASC is also involved in inflammasome activation in zebrafish. When overexpressed in vitro and in vivo in zebrafish, both the zASC and zASC pyrin domain (PYD)proteins form speck and filament structures. Importantly, the crystal structures of the N-terminal PYD and C-terminal CARD of zebrafish ASC were determinedindependently as two separate entities fused to maltose-binding protein (MBP). Structure-guided mutagenesis revealed the functional relevance of the PYD hydrophilic surface found in the crystal lattice. Finally, the fish caspase-1 homolog Caspy, but not the caspase-4/11 homolog Caspy2, interacts with zASC through homotypic PYD-PYD interactions, which differ from those in mammals. These observations establish the conserved and unique structural/functional features of the zASC-dependent inflammasome pathway.