Investigation of the role of an amino acid triplet repeat in differentiating drug-receptor interaction at m1 and m2 muscarinic receptors

Pharmacology
S Z ZhuE E el-Fakahany

Abstract

The first putative extracellular domains of both m1 and m2 muscarinic receptors contain a triplet of amino acid residues consisting of leucine (L), tyrosine (Y), and threonine (T). This triplet is repeated as LYTLYT in m2 receptors. However, it is repeated in a transposed fashion (LYTTYL) in the sequence of m1 receptors. In this work we employed site-directed mutagenesis to investigate the possible significance of this unique sequence diversity in determining the distinct differential drug-receptor interaction at the two receptor subtypes. Mutation of the LYTTYL sequence of m1 receptors to the corresponding m2 receptor LYTLYT sequence, however, did not significantly change the binding affinity of the agonist carbachol or the affinity of the majority of a series of receptor antagonists which are able to discriminate between wild-type m1 and m2 receptors. The reverse mutation at the m2 receptor also did not modify agonist affinity, but altered affinity of several receptor subtype-selective antagonists. The magnitude of affinity changes, however, was small, and the direction of these changes was opposite to what would be expected if the m2 receptor LYTLYT seqence were important for determining the binding profile of m2-receptor-se...Continue Reading

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.