Prof Neva Caliskan

Recoding Mechanisms in Infections

Our research and approach

The research group lead by Neva Caliskan investigates functions and dynamics of RNA molecules in non-canonical translation events, which can affect the interplay between the host and pathogen during infection. Ultimately, they seek to illuminate therapeutic RNA-protein complexes as novel targets to combat infections.

Viruses and cellular genes encode RNAs that can be read in alternative ways during translation, which is called recoding. However, how exactly recoding is regulated by host encoded factors remains elusive. Here, a detailed understanding of recoding and its regulation can open doors for the development of novel RNA-based therapeutic interventions to combat infections.

Neva Caliskan’s group investigates the functions and dynamics of RNA molecules and their interplay with trans-acting factors involved in recoding events. They work with several viruses known to depend on recoding strategies for replication including corona and retroviruses, and develop methods to investigate RNA complexes and translation in unprecedented detail.

The group employs a highly interdisciplinary toolset including RNA-antisense purification and mass spectrometry to identify RNA-interaction partners, and cellular assays to investigate molecular details. Ensemble and single molecule assays such as optical tweezers are key to study the dynamics of RNA complexes. Ultimately, they seek to understand how RNA-structure elements act in concert with other factors in the cell to modulate the way mRNA messages are read by ribosomes during infections to advance RNA-based therapeutics.

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Graphical Abstract

The research foci of the Caliskan lab
Graphical abstract © Helmholtz Institute Würzburg / Sandy Westermann

Peering into the black box

Many bacterial and viral pathogens and also their eukaryotic host cells employ non-canonical translation strategies in order to express hidden genes from alternative open reading frames (Caliskan et al., 2015). RNA is a versatile molecule that acts as a key regulator of non-canonical translation events. RNA can exist in various shapes and interact with other regulatory elements such as ncRNAs, small molecules and proteins to alter the meaning of the message encoded in the primary sequence of the mRNA. How RNA structure and regulatory elements drive alternative translation events is currently not fully understood. In addition, it is largely unclear to what extend these translation events are used by the pathogen and the host cell during infections. We use cutting-edge RNA analytics, such as ribosome profiling and deep sequencing combined with single molecule and computational tools to understand dynamics of translation and the functions of RNA regulators during infections. Ultimately, we want to better understand the interplay between the host’s and pathogen’s gene expression and harness our knowledge to develop novel therapeutic strategies to combat infectious diseases.

The POTATO TOOL: DATA ANALYSIS MAde easy

The single-molecule technique known as optical tweezers allows probing of intra- and intermolecular interactions that govern complex biological processes. Recent developments have made it easier to collect data, yet it remains difficult to analyze it. To enable high-throughput data analysis, we developed an automated Python-based analysis pipeline called POTATO (practical optical tweezers analysis tool). POTATO uses predefined parameters to automatically process the high-frequency raw data generated by force-ramp experiments and to identify (un)folding events. Our research was published in the Biophysical Journal.

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Silver linings in the pandemic

Scientists from Neva Caliskan’s research group and other HIRI and HZI labs demonstrate for the first time how ZAP, a protein of the human immune defense system, inhibits the replication mechanism of the SARS-CoV-2 coronavirus and can reduce the viral load by 20-fold. The findings were published in the journal Nature Communications and may help develop antiviral agents in the fight against the pandemic.