Three IMP PhD students awarded prestigious DOC Fellowships from the Austrian Academy of Sciences
Johannes Suwita, Myrto Chatziangelou, and Constanze Gremmelmaier, PhD students at the IMP, have been awarded prestigious DOC Fellowships by the Austrian Academy of Sciences (ÖAW). The fellowships will support their doctoral research on fertilisation mechanisms, long-range gene regulation, and splicing quality control, conducted in the labs of Andrea Pauli, Alexander Stark, and Clemens Plaschka respectively.
Johannes Suwita, Myrto Chatziangelou, and Constanze Gremmelmaier, PhD students at the IMP, have been awarded DOC Fellowships by the Austrian Academy of Sciences (ÖAW). These competitive fellowships support highly qualified doctoral candidates across all fields of research, enabling them to focus fully on completing their PhD theses within a defined timeframe.
Suwita, Chatziangelou, and Gremmelmaier are members of the Vienna BioCenter PhD Program and they conduct their doctoral research at the IMP in the labs of Andrea Pauli, Alexander Stark, and Clemens Plaschka respectively. The DOC Fellowship will support their efforts to discover fundamental molecular mechanisms in fertilisation, gene regulation, and the quality control of RNA splicing.
Discovering the molecular basis of fertilisation
Fertilisation—the fusion of sperm and egg—is one of the most fundamental biological processes, yet the molecular details of how gametes recognise and merge with one another remain incompletely understood. In the Pauli lab, Johannes Suwita studies how sperm-egg binding and fusion are orchestrated on a molecular level.
Recent work from the Pauli lab has identified a trimeric complex of three conserved sperm surface proteins—Tmem81, Izumo1, and Spaca6—that bridges sperm and egg in both fish and mammals. Building on these findings, Suwita aims to discover the role of additional sperm proteins involved in this process. Using biochemical and structural biology tools, he is exploring how these molecules interact with the known trimer and contribute to successful gamete fusion.
Before joining the IMP in October 2023, Suwita studied biochemistry at the University of Regensburg, earning both his bachelor's and master's degrees. He was awarded the “Deutschlandstipendium” and was a fellow of the Max Weber-Programm of the Elite Network of Bavaria. As part of his master’s training, he conducted a research internship in the lab of Jim Goodrich and Jennifer Kugel at the University of Colorado Boulder, where he focused on single-molecule fluorescence microscopy. For his master’s thesis, he joined the lab of Alessandro Vannini at the Human Technopole in Milan, where he used cryo-electron microscopy to investigate the structure and function of human condensin I.
How distant enhancers regulate gene expression
In complex genomes, enhancers can regulate genes from hundreds of kilobases away, playing a critical role in development and cellular identity. Yet the molecular players that enable this long-range communication between enhancers and promoters remain poorly understood. In her PhD project, Myrto Chatziangelou is working to identify novel regulators that specifically facilitate these distal interactions.
Working in the Stark lab, Chatziangelou is developing a system in mouse embryonic stem cells to pinpoint proteins—termed “long-range regulators”—that mediate enhancer-promoter communication across large genomic distances. These factors may act through previously uncharacterised DNA elements and are hypothesised to be essential for maintaining proper gene expression. Her work aims to fill a major gap in our understanding of transcriptional regulation and may provide insights into diseases linked to enhancer mis-regulation.
Before joining the IMP in April 2024, Chatziangelou earned both her bachelor's and master's degrees in Biochemistry and Biotechnology at the University of Thessaly in Greece. Her master’s thesis focused on the gene regulation of cancer-specific long non-coding RNAs (lncRNAs).
An atomic look at the cell's molecular editor
Accurate splicing of precursor messenger RNAs (pre-mRNAs) is essential for proper gene expression in eukaryotic cells. This complex process is carried out by the spliceosome—a large, dynamic molecular machine that assembles anew on each pre-mRNA transcript. To ensure fidelity, the spliceosome must undergo a series of tightly regulated conformational changes, forming a catalytic core capable of removing non-coding sequences and joining together protein-coding sequences. How the spliceosome maintains quality control during the process remains an open question in the field.
In her PhD project, Constanze Gremmelmaier is studying the mechanisms of splicing quality control. Using an integrated structural biology approach, she combines cryo-electron microscopy (cryo-EM) with molecular biology and biochemical techniques to discover the mechanisms ensuring that pre-mRNAs are spliced correctly and efficiently which contributes to accurate gene expression.
Gremmelmaier completed her bachelor’s studies in biochemistry at the University of Tübingen, with further studies at Uppsala University and the University of Montréal. She graduated in biochemistry with a master's degree from the Technical University of Munich (TUM) before joining the IMP as a PhD student in the Plaschka lab.
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