Evolution of ligands, receptors and metabolizing enzymes of thyroid signaling.
Thyroid hormones (THs) play important roles in vertebrates such as the control of the metabolism, development and seasonality. Given the pleiotropic effects of thyroid disorders (developmental delay, mood disorder, tachycardia, etc), THs signaling is highly investigated, specially using mammalian models. In addition, the critical role of TH in controlling frog metamorphosis has led to the use of Xenopus as another prominent model to study THs action. Nevertheless, animals regarded as non-model species can also improve our understanding of THs signaling. For instance, studies in amphioxus highlighted the role of Triac as a bona fide thyroid hormone receptor (TR) ligand. In this review, we discuss our current understanding of the THs signaling in the different taxa forming the metazoans (multicellular animals) group. We mainly focus on three actors of the THs signaling: the ligand, the receptor and the deiodinases, enzymes playing a critical role in THs metabolism. By doing so, we also pinpoint many key questions that remain unanswered. How can THs accelerate metamorphosis in tunicates and echinoderms while their TRs have not been yet demonstrated as functional THs receptors in these species? Do THs have a biological effect in insects and cnidarians even though they do not have any TR? What is the basic function of THs in invertebrate protostomia? These questions can appear disconnected from pharmacological issues and human applications, but the investigation of THs signaling at the metazoans scale can greatly improve our understanding of this major endocrinological pathway.
Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
Guillaume
G
Holzer
Laboratoire de Biologie Intégrative des Organismes Marins UMR 7232, CNRS et Université Pierre et Marie Curie, Avenue Pierre Fabre, 66650 Banyuls-sur-Mer, France.
Natacha
N
Roux
Laboratoire de Biologie Intégrative des Organismes Marins UMR 7232, CNRS et Université Pierre et Marie Curie, Avenue Pierre Fabre, 66650 Banyuls-sur-Mer, France. Electronic address: vincent.laudet@obs-banyuls.fr.
Vincent
V
Laudet
D000818:Animals; D005075:Biological Evolution; D003063:Cnidaria / Q000033:anatomy & histology / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007313:Insecta / Q000033:anatomy & histology / Q000502:physiology; D007453:Iodide Peroxidase / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D010802:Phylogeny; D011988:Receptors, Thyroid Hormone / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013045:Species Specificity; D013961:Thyroid Gland / Q000502:physiology*; D013974:Thyroxine / Q000235:genetics / Q000378:metabolism*; D014284:Triiodothyronine / Q000031:analogs & derivatives / Q000235:genetics / Q000378:metabolism*
D008024:Ligands; D011988:Receptors, Thyroid Hormone; D014284:Triiodothyronine; C010642:3,3',5-triiodothyroacetic acid; D007453:Iodide Peroxidase; D013974:Thyroxine
Evolution; T3; Thyroid hormone receptor; Triac; Triiodothyroacetic acid; Triiodothyronine