Enzymes are biological catalysts crucial for all cellular functions in every biological system. Most enzymes are proteins, and their ability to specifically accelerate chemical reactions by orders of magnitude relies on their structure, dynamics and allosteric regulation. Our lab utilizes cutting-edge molecular methods in order to delineate the structural basis underlying the activity and regulatory mechanisms of two types of enzymes: Ion channels, catalyzing the movement of ions across cell membranes, and prenyltransferases, synthesizing moieties for post-translational protein modification. Importantly, both types of enzymes are essential for cell survival and proliferation, and mutations or alterations in their expression levels are involved in human diseases.
- Our lab focuses on understanding how the molecular architectures of proteins are funneled into their specialized activities.
Given the emerging and pivotal roles of ion channel and prenyltransferases in numerous human diseases, we aim to provide novel molecular insights that may facilitate the future development of targeted therapeutic strategies.
To do so, we use a wide array of approaches:
To follow dynamic molecular conformational rearrangements
Advanced protein biochemistry
Reconstitution of purified proteins an predefined environments
Allows unparalleled temporal resolution measurements of protein function
To follow dynamic molecular conformational rearrangements
High-throughput mutant screening
For understanding the pathophysiological mechanisms of enzyme-related diseases
Small molecule binding assays
For identifying novel therapeutic leads
Current research projects in the lab
Anion selective channels, one of the least understood families of ion channels, are known to be expressed in microglial cells and contribute to the cellular activation and oxidative burst processes. However, the exact molecular mechanisms enabling these channels to participate in immune cells response, as well as their regulation, are largely missing.
Microglial cells are the backbone of brain immunity. Any disturbance or loss of brain homeostasis evokes a rapid transformation of resting microglia into an activated or phagocytic state. Immunological receptors, ion channels, and other signalling cascades orchestrate the activation of microglia, leading to enhanced proliferation, migration, phagocytosis, and to the production of pro-inflammatory cytokines/chemokines and reactive oxygen species. However, microglial activation can be a double-edged sword, exacerbating acute central nervous system pathologies including stroke, and neurodegenerative disorders such as Alzheimer’s and Parkinson’s diseases. Anion channels are important for the maintenance of the ramified morphology of resting microglia, support chemokine-induced migration, drive the morphological changes required for engulfment and phagocytosis, and counterbalance changes in membrane potential initiated by superoxide anion flux. Nevertheless, the molecular identity of anion channels expressed in microglia is still debated. Additionally, little is known about the gating and physiological modulation of these channels.
In our lab, using molecular and biochemical approaches, we study both structural and functional aspects of two families of anion selective ion channels, central for microglial activity: the Ca2+-activated anion channels (CaCC) and the enigmatic chloride intracellular channels (CLIC).
Although often envisioned as a single pore-forming arrangement surrounded by a sea of lipid molecules, ion channels are in fact usually the center of multi-component complexes. These structures serve to link ion channels to supportive and instructive signaling pathways and cellular networks, providing addition indication for their critical roles in cellular function.
Members of the KCNH voltage-dependent potassium channel family are important regulators of cellular excitability and have key roles in diseases such as cardiac arrhythmia, Long QT syndrome (LQT2), epilepsy and schizophrenia. Moreover, EAG channels are known to play important roles in cancer biology, by contributing to cell cycle progression and proliferation. As KCNH channels are known to serve as docking hubs of multiple regulatory proteins, we currently pursue their mechanisms of interaction and modes of regulation.
We are interested in understanding how ion channels work and how different proteins regulate their function. To do so, we employ a wide variety of electrophysiological, biochemical and structural approaches, including advanced fluorescence and electrophysiological methods enabling the detection of very subtle conformational changes with high temporal resolution.
Cancer cells acquire hallmark properties which arm them with abnormally enhanced proliferative potential and reduced dependence on environmental cues, leading to tumor growth and metastasis. These hallmarks are obtained in part by extensively rewiring metabolic pathways essential for cell survival. Rewired post-translational protein modifications support the malignant characteristics of cancer cells. Thus, inhibition of key enzymes in this pathway represents a novel yet under-explored therapeutic venue for anti-cancer drug design.
Our group has recently established a multidisciplinary approach to elucidate the structural and functional properties of prenyltransferases, key enzymes crucial for various post-translational modification pathways, which may serve as viable and novel targets for cancer treatment. In this project, using cutting-edge multi-disciplinary molecular approaches, we aim to elucidate the structural mechanisms governing prenyltransferases’ function. Furthermore, with our overarching goal of developing novel therapeutic approaches for cancer, we currently establish and utilize high-throughput platforms for the identification of agents that target and inhibit members of this enzyme superfamily.