We study the physiology, biochemistry and pharmacology of cholinergic neurons at molecular level. In our study we mainly employ cell lines but we also use animal models. Our research is focused mainly on these topics:
- Biochemical physiology and pharmacology of cholinergic neurons. Development and differentiation of cholinergic neurons. Synthesis, storage, and release of acetylcholine. Presynaptic regulation of acetylcholine release.
- Cholinergic mechanisms in pathogenesis of Alzheimer´s disease. Influence of beta-amyloid on acetylcholine metabolism and muscarinic transmission.
- Molecular pharmacology of muscarinic receptors. Allosteric modulation of receptor activation. Interaction of muscarinic receptors with G-proteins. Modeling of muscarinic receptor signal transduction.
Projects
Cholesterol has been found to co-crystallize with a number of GPCRs. Our current experiments show that membrane cholesterol specifically binds to a muscarinic receptor and slows down their activation.
More
A biased agonist is a ligand which stabilizes a particular active conformation of a receptor, thus stimulating some responses but not others. Biased agonists might represent a novel and uniquely effective type of therapeutic agent with reduced side-effects.
More
The aim of the project is to determine how disruption of cholinergic activation of striatal GABAergic interneurons alters striatal signalling and striatum-based behaviour by using a mouse model with deletion of the β2 nicotinic acetylcholine receptor subunit in striatal GABAergic interneurons.
More
Ectopic agonists represent a new class of drugs that bind out of the orthosteric site and display unique functional selectivity through mechanisms yet to be defined. We perform a detailed analysis of receptor activation induced by ectopic and classical agonists with the aim to reveal molecular mechanisms underlying functional selectivity.
More
Achievements
Proper determination of agonist efficacy is essential in the assessment of agonist selectivity and signalling bias. Agonist efficacy is a relative term that is dependent on the system in which it is measured, especially being dependent on receptor expression level. In this work, we analyse limits and pitfalls of fitting OM to experimental data.
More
Our new publication in journal Neuropharmacology in which we demonstrate that membrane cholesterol plays an important and subtype-specific role in activation of muscarinic acetylcholine receptors. To our knowledge, this is the first demonstration of pharmacological selectivity due to differences in receptor-membrane interactions at any GPCR. The possibility to achieve pharmacological selectivity based on receptor-membrane interactions changes our view on the molecular basis of pharmacological selectivity and opens new ways for the development of a novel pharmaceutics.
More
In this study, we have developed new potent and long-acting antagonists of muscarinic acetylcholine receptors with a potential therapeutic use.
More
In collaboration with Barry University novel muscarinic antagonists were developed.
More
This article analyzes in atomistic detail binding of orthosteric ligands to the muscarinic receptors.
More
Show more
Publications
Jakubík, Jan - Randáková, Alena - Rudajev, Vladimír - Zimčík, Pavel - El-Fakahany, E. E. - Doležal, Vladimír
.
Applications and limitations of fitting of the operational model to determine relative efficacies of agonists
.
Scientific Reports 2019, 9(Mar 15)), 4637
.
IF = 4.011
[ASEP]
[
doi
]
Jakubík, Jan - Randáková, Alena - El-Fakahany, E. E. - Doležal, Vladimír
.
Analysis of equilibrium binding of an orthosteric tracer and two allosteric modulators
.
PLoS ONE 2019, 14(3)), e0214255
.
IF = 2.776
[ASEP]
[
doi
]
Randáková, Alena - Rudajev, Vladimír - Doležal, Vladimír - Boulos, J. - Jakubík, Jan
.
Novel long‐acting antagonists of muscarinic ACh receptors
.
British Journal of Pharmacology 2018, roč. 175, 10, p. 1731-1743
.
IF = 6.583
[ASEP]
[
doi
]
Randáková, Alena - Dolejší, Eva - Rudajev, Vladimír - Zimčík, Pavel - Doležal, Vladimír - El-Fakahany, E. E. - Jakubík, Jan
.
Role of membrane cholesterol in differential sensitivity of muscarinic receptor subtypes to persistently bound xanomeline
.
Neuropharmacology 2018, roč. 133, May 1, p. 129-144
.
IF = 4.367
[ASEP]
[
doi
]
Boulos, J. F. - Jakubík, Jan - Boulos, J. M. - Randáková, Alena - Momirov, J.
Synthesis of novel and functionally selective non‐competitive muscarinic antagonists as chemical probes
.
Chemical Biology & Drug Design 2018, roč. 91, 1, p. 93-104
.
IF = 2.256
[ASEP]
[
doi
]
Show more
Department of Neurochemistry
Department of Neurochemistry
Department of Neurochemistry, July 2016
Model of postsynaptic membrane. βA fibril, ACh - acetylcholine, APP - amyloid precursor protein, Go G-protein, Kir - inward rectifying potassium channel, M2 muscarinic receptor
Acetylcholine (ACh) is synthesized from choline and acetylcoenzyme A (AcCoA) by cholineacetyl transferase (ChAT) in cytoplasm of synaptic ending of neuron. ACh is transported into vesicles by vesicular acetylcholin transporter (VAChT) where it is stored untill release. Upon arrival of the signal in form of action potential to the synaptic ending vesicles fuse with plasma membrane and ACh is released to synaptic cleft. On post-synaptic membrane ACh either opens non selective cation channels - nicotinic receptors (NAChR) - or activates G protein coupled muscarinic receptors (MAChR). ACh may regulates its release via interaction with presynaptic MAChR. Action of ACh is terminated by acetylcholine esterase that cleaves it to inactive choline and acetate. Choline is transported back by to synaptic ending by choline transporter (ChT).
