lipid modifications of proteins
THE ROLE OF LIPID MODIFICATIONS OF PROTEINS IN FUNCTIONAL NEURONAL PLASTICITY, LEARNING AND MEMORY
National Science Centre 2019/34/E/NZ4/00387
keywords: neuronal plasticity, learning and memory, dopamine, hippocampus, electrophysiology, palmitoylation, molecular biology, imaging
The hallmark of the mammalian brain is the ability of processing and store information in synapses and highly organized neuronal networks. The brain can adapt and change in response to various events under physiological conditions (i.e. learning and memory formation) and pathological conditions (i.e. epilepsy, stroke). Understanding the fundamental mechanisms governing the plasticity of synaptic connections and neuronal network code lies in the center of contemporary neuroscience, neuropharmacology, and medicine. The identification of posttranslational modifications (PTMs) opened a new dimension of how we understand protein structure and cellular function. In the last decade, reversible lipid modification of proteins called S-palmitoylation (S-PALM) has been shown to dynamically regulate the localization of several neuronal synaptic and non-synaptic proteins in vitro. However, the time-course and the functional consequences of S-PALM in neurons, its role in neural plasticity and learning remains unknown. Processes like a reward, motor function, and cognition are modulated by the neurotransmitter dopamine (DA). Novelty-driven DA release to the hippocampus is indispensable for the conversion of short-term memories to long-term ones (memory consolidation). Interestingly, in vitro, recombinant DA receptors and transporters are subject to S-PALM.
Our current project focuses on the description of the time-course of S-PALM following various patterns of neuronal activity and the role of protein S-PALM in dopamine- and hippocampus-dependent learning.
We use a multidisciplinary approach to study general mechanisms governing brain plasticity in the physiological and pathophysiological states. Currently, we implement biochemical tools allowing detection of protein modifications in the nervous tissue (i.e. acyl-biotinyl exchange in brain homogenates and synaptoneurosomes) and mass spectrometry. To study functional aspects of neuronal networks, we combine pharmacology and single-cell patch-clamp technique or field potentials recording in primary hippocampal neurons and acute brain slices. Alternatively, we use Multi-Electrode-Arrays for long-term recordings of neuronal network activity. We also use immunofluorescence as well as live Ca2+ imaging to study Ca2+ dynamics in neurons and astrocytes. Recently we have introduced slice cultures where genes of interest are manipulated with viral vectors.