29.1. 2024, Neurochemie

PhD project: Mechanisms of selective modulation of individual subtypes of muscarinic receptors

The disruption of muscarinic signalling is frequently involved in various pathophysiological conditions, including neuropathic pain, neurological and psychiatric disorders, e.g. Alzheimer's disease or schizophrenia, and some internal diseases, e.g. asthma or overactive bladder. To target these particular conditions, selective modulation of individual muscarinic subtypes is necessary to avoid undesired side effects. High homology of the orthosteric binding site among all muscarinic subtypes makes a finding of subtype-selective orthosteric agonists virtually unattainable. Selective targeting at a particular G-protein-mediated signalling pathway by biased agonists, exerted by agonist-specific conformation, can be the right way to achieve selectivity among individual subtypes of muscarinic receptors. On the other hand, bulky muscarinic antagonists, allosteric or bitopic ligands have a better chance to interact with less conserved areas of muscarinic receptors and achieve binding selectivity for individual muscarinic subtypes. Recently described muscarinic orthosteric agonists containing tetrahydropyridin and thiophene moieties display signalling bias toward Gi/o G-proteins and thus M2/M4 functional selectivity. Further, bitopic antagonists containing tetrahydropiridin moiety and O-hexyl chain act as M1 preferring long-acting antagonists. Accurate pharmacological analysis of the signalling profile and elucidation of mechanisms leading to the selectivity of these new compounds may facilitate the development of desired functionally selective agonists and antagonists. This project aims to perform a detailed binding and functional analysis of newly synthesized agonists and antagonists based on tetrahydropyridine. Further, we will employ site-directed mutagenesis of receptors and molecular modelling of ligand-receptor interactions to study the mode of action of these compounds.

Candidate’s profile (requirements):

We are seeking highly motivated independent candidate with a master's degree or equivalent in pharmacology, biochemistry, molecular biology or related fields, or those expecting to obtain their degree this year. Essentially, candidate should be fluent in English and willing to travel to collaborating laboratories abroad to learn new techniques required for this project. Experience with in vitro cell culture, molecular biology techniques and basic programming skills are an advantage.

Supervisor: Jan Jakubik, PhD

References:

• Randáková A and Jakubík J, Functionally selective and biased agonists of muscarinic receptors. Pharmacol Res. 2021;169:105641. doi: 10.1016/j.phrs.2021.105641
• Randáková A, et al., Agonist-Specific Conformations of the M2 Muscarinic Acetylcholine Receptor Assessed by Molecular Dynamics. J Chem Inf Model. 2020; 27;60(4):2325-2338. doi: 10.1021/acs.jcim.0c00041.
• Randáková A, et al., Novel M2 -selective, Gi -biased agonists of muscarinic acetylcholine receptors. Br J Pharmacol. 2020;177(9):2073-2089. doi: 10.1111/bph.14970.
• Randáková A, et al, Novel long-acting antagonists of muscarinic ACh receptors. Br J Pharmacol. 2018; 175(10):1731-1743. doi: 10.1111/bph.14187