Thyroid hormone biosynthesis and release.
Thyroid hormones (TH) 3,5,3',5'- tetraiodothyronine or thyroxine (T4) and 3,5,3'- triiodothyronine (T3) contain iodine atoms as part of their structure, and their synthesis occur in the unique structures called thyroid follicles. Iodide reaches thyroid cells through the bloodstream that supplies the basolateral plasma membrane of thyrocytes, where it is avidly taken up through the sodium/iodide symporter (NIS). Thyrocytes are also specialized in the secretion of the high molecular weight protein thyroglobulin (TG) in the follicular lumen. The iodination of the tyrosyl residues of TG preceeds TH biosynthesis, which depends on the interaction of iodide, TG, hydrogen peroxide (H2O2) and thyroid peroxidase (TPO) at the apical plasma membrane of thyrocytes. Thyroid hormone biosynthesis is under the tonic control of thyrotropin (TSH), while the iodide recycling ability is very important for normal thyroid function. We discuss herein the biochemical aspects of TH biosynthesis and release, highlighting the novel molecules involved in the process.
Biophysics Institute of Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: dencarv@gmail.com.
Denise P
DP
Carvalho
Université Paris-Saclay, Orsay, France; UMR 8200 CNRS, Villejuif, France; Institut de Cancérologie Gustave Roussy, Villejuif, Ile-de-France, France.
Corinne
C
Dupuy
D000818:Animals; D001324:Autoantigens / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D018118:Chloride Channels / Q000378:metabolism; D006801:Humans; D007453:Iodide Peroxidase / Q000378:metabolism; D033862:Iron-Binding Proteins / Q000378:metabolism; D015394:Molecular Structure; D027981:Symporters / Q000378:metabolism; D000072637:Thyroid Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D013963:Thyroid Hormones / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism*; D013974:Thyroxine / Q000096:biosynthesis / Q000378:metabolism; D014284:Triiodothyronine / Q000096:biosynthesis / Q000378:metabolism; D000099209:Sodium-Iodide Symporters
D001324:Autoantigens; D018118:Chloride Channels; D007453:Iodide Peroxidase; D033862:Iron-Binding Proteins; D027981:Symporters; D013963:Thyroid Hormones; D013974:Thyroxine; D014284:Triiodothyronine; D000099209:Sodium-Iodide Symporters; C056658:TPO protein, human
Anoctamin-1; ClC5; DUOX; NIS; Pendrin; TPO; Thyroglobulin