Gene duplication plays a major role in gene co-option: Studies into the evolution of the motilin/ghrelin family and their receptors

Preliminary discussion on the mechanism of active components of Radix Aconiti kusnezoffii in the treatment of migraine based on network pharmacology

To investigate the mechanism of action of Cao Wu in the treatment of migraine from the perspective of network pharmacology. The Swiss Target Prediction Database and CTD database were used to predict the target information of Cao Wu. Human Genome Database gene cards were used to find migraine-related target genes. The target protein interaction network and the "active ingredient-target" network were obtained by combining Cytoscape 3.7.1 software and R language. Enrichment analysis of the Kyoto Encyclopedia of Genes and Genomes pathway and gene function analysis (GO) were performed using the R language to preliminarily explore the multiple pharmacological mechanisms of Radix Aconiti kusnezoffii. Forty-three indicators were identified. A total of 176 migraine targets were identified through the genecards database and OMIM database. Radix Aconiti kusnezoffii targets were compared with migraine targets and 12 overlapping targets were extracted. The protein interaction network of the overlapping targets was analyzed to identify the key targets for the drug to affect the disease. In addition, Kyoto Encyclopedia of Genes and Genomes pathway and go function enrichment analyses were performed on the overlapping targets to explore the therapeutic mechanism of migraine. The treatment of migraine with herbal woo is characterized by multi-component, multi-target, and multi-channel, which exerts complex network regulation through the interaction between different targets, providing a new idea and basis for further exploring the mechanism of action of herbal woo in the treatment of migraine.

Why is motilin active in some studies with mice, rats, and guinea pigs, but not in others? Implications for functional variability among rodents

The gastrointestinal (GI) hormone motilin helps control human stomach movements during hunger and promotes hunger. Although widely present among mammals, it is generally accepted that in rodents the genes for motilin and/or its receptor have undergone pseudonymization, so exogenous motilin cannot function. However, several publications describe functions of low concentrations of motilin, usually within the GI tract and CNS of mice, rats, and guinea pigs. These animals were from institute‐held stocks, simply described with stock names (e.g., “Sprague–Dawley”) or were inbred strains. It is speculated that variation in source/type of animal introduces genetic variations to promote motilin‐sensitive pathways. Perhaps, in some populations, motilin receptors exist, or a different functionally‐active receptor has a good affinity for motilin (indicating evolutionary pressures to retain motilin functions). The ghrelin receptor has the closest sequence homology, yet in non‐rodents the receptors have a poor affinity for each other's cognate ligand. In rodents, ghrelin may substitute for certain GI functions of motilin, but no good evidence suggests rodent ghrelin receptors are highly responsive to motilin. It remains unknown if motilin has functional relationships with additional bioactive molecules formed from the ghrelin and motilin genes, or if a 5‐TM motilin receptor has influence in rodents (e.g., to dimerize with GPCRs and create different pharmacological profiles). Is the absence/presence of responses to motilin in rodents’ characteristic for systems undergoing gene pseudonymization? What are the consequences of rodent supplier‐dependent variations in motilin sensitivity (or other ligands for receptors undergoing pseudonymization) on gross physiological functions? These are important questions for understanding animal variation.

Adaptive evolution of GPR39 in diverse directions in vertebrates

G protein-coupled receptors (GPCRs) play an important role in physiology and disease and represent productive drug targets. Orphan GPCRs, which have unknown endogenous ligands, are considered drug targets and consequently have attracted great interest in identifying their endogenous cognate ligands for deorphanization. However, additional studies have shown that GPCRs, including many orphan GPCRs, can constitutively activate G protein signaling in a ligand-independent manner. GPR39 is such an orphan GPCR with constitutive activity. Here, we performed a phylogenetic and selection analysis of GPR39 in vertebrates, and we found that GPR39 underwent positive selection in different branches of vertebrates. Using luciferase reporter assays, we demonstrated that human, frog and chicken GPR39 can constitutively activate Gq and G12 signaling pathways in a ligand-independent manner. Zebrafish GPR39 can constitutively activate Gs, Gq and G12 signaling pathways in a ligand-independent manner. We further found that the zebrafish-H296^7.35 site is crucial for the activity of the Gs signaling pathway. In addition, our mutagenesis studies indicated that the positive selection sites of GPR39 from different species had important effects on the constitutive activity of the receptor. Our results revealed the adaptive evolution of GPR39 in diverse directions, which led to differences in constitutive activity.