I am originally from Argentina where I studied Biology and completed my PhD at the University of Córdoba. Currently, I work as postdoc at the Centre for Organismal Studies (COS) in Heidelberg, Germany.
During my PhD, I worked on characterizing the novel cytokinin transporter family AZG, which is involved in plant hormonal transport and signaling. This sparked my interest in plant development and morphogenesis and put me in contact with Prof. Dr. Alexis Maizel. He helped me to outline my postdoctoral projects, which involves identifying protein interactors in specific developmental contexts using biotin proximity labeling.
We are currently working on two main research projects at COS. The first project aims to find interactors of ARGONAUTE proteins to better understand the biogenesis of siRNAs. The second project involves establishing Split-Proximity Labeling in plant models to understand the signaling pathways behind asymmetric cell growth during lateral root morphogenesis.
Sunday session 2
Deciphering AGO7 interactome to understand siRNA bodies' composition and dynamics in the context of stress
T.M. Tessi, Z. Ma, A. Maizel
Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
AtAGO1 and AtAGO7 are the main effectors of post-transcriptional gene silencing in Arabidopsis. At AGO7 is a crucial component of the tasiRNA biogenesis pathway, which plays a crucial role in the development of leaf, flower, and root systems by targeting the auxin response factors AtARF3/4 for silencing. We conducted a proximity labelling study and found that AtFIM5, an actin-associated protein, is highly abundant in the vicinity of AtAGO7. Given that the tasiRNA biogenesis machinery localizes to the membraneless siRNA bodies that move along the actin cytoskeleton, we investigated the potential role of AtFIM5 in siRNA body dynamics. We found that AtFIM5 localization is stress-responsive and changes in AtFIM5 behaviour impact on siRNA bodies shape and movement. Additionally, we identified several putative AtAGO7 interactors that colocalize with siRNA bodies and have the potential to generate liquid-liquid phase-separated condensates. Our research aims to understand the impact of stress onto siRNA body dynamics, composition, and fluidity. We believe that unravelling the fine regulation of these condensates will shed light on long-standing questions such as how the biogenesis of secondary sRNA is favoured over RNA degradation. The integration of stress biology into tasi RNA metabolism may pave the way for innovative breeding strategies for more resilient crops.