Thyroid Hormone Receptors alpha
High affinity receptors for THYROID HORMONES, especially TRIIODOTHYRONINE. These receptors are usually found in the nucleus where they regulate DNA transcription. They are encoded by the THRA gene (also known as NR1A1, THRA1, ERBA or ERBA1 gene) as several isoforms produced by alternative splicing.
Receptors, Thyroid Hormone
Specific high affinity binding proteins for THYROID HORMONES in target cells. They are usually found in the nucleus and regulate DNA transcription. These receptors are activated by hormones that leads to transcription, cell differentiation, and growth suppression. Thyroid hormone receptors are encoded by two genes (GENES, ERBA): erbA-alpha and erbA-beta for alpha and beta thyroid hormone receptors, respectively.
Thyroid Hormones
Triiodothyronine
A T3 thyroid hormone normally synthesized and secreted by the thyroid gland in much smaller quantities than thyroxine (T4). Most T3 is derived from peripheral monodeiodination of T4 at the 5' position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3.
Thyroid Hormone Receptors beta
High affinity receptors for THYROID HORMONES, especially TRIIODOTHYRONINE. These receptors are usually found in the nucleus where they regulate DNA transcription. They are encoded by the THRB gene (also known as NR1A2, THRB1, or ERBA2 gene) as several isoforms produced by alternative splicing. Mutations in the THRB gene cause THYROID HORMONE RESISTANCE SYNDROME.
Oncogene Proteins v-erbA
Transforming proteins encoded by erbA oncogenes from the avian erythroblastosis virus. They are truncated versions of c-erbA, the thyroid hormone receptor (RECEPTORS, THYROID HORMONE) that have retained both the DNA-binding and hormone-binding domains. Mutations in the hormone-binding domains abolish the transcriptional activation function. v-erbA acts as a dominant repressor of c-erbA, inducing transformation by disinhibiting proliferation.
Hypothyroidism
A syndrome that results from abnormally low secretion of THYROID HORMONES from the THYROID GLAND, leading to a decrease in BASAL METABOLIC RATE. In its most severe form, there is accumulation of MUCOPOLYSACCHARIDES in the SKIN and EDEMA, known as MYXEDEMA.
Thyroxine
The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.
Retinoid X Receptors
A subtype of RETINOIC ACID RECEPTORS that are specific for 9-cis-retinoic acid which function as nuclear TRANSCRIPTION FACTORS that regulate multiple signaling pathways.
Thyroid Gland
A highly vascularized endocrine gland consisting of two lobes joined by a thin band of tissue with one lobe on each side of the TRACHEA. It secretes THYROID HORMONES from the follicular cells and CALCITONIN from the parafollicular cells thereby regulating METABOLISM and CALCIUM level in blood, respectively.
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Receptors, Cytoplasmic and Nuclear
Intracellular receptors that can be found in the cytoplasm or in the nucleus. They bind to extracellular signaling molecules that migrate through or are transported across the CELL MEMBRANE. Many members of this class of receptors occur in the cytoplasm and are transported to the CELL NUCLEUS upon ligand-binding where they signal via DNA-binding and transcription regulation. Also included in this category are receptors found on INTRACELLULAR MEMBRANES that act via mechanisms similar to CELL SURFACE RECEPTORS.
Base Sequence
Thyroid Hormone Resistance Syndrome
An inherited autosomal recessive trait, characterized by peripheral resistance to THYROID HORMONES and the resulting elevation in serum levels of THYROXINE and TRIIODOTHYRONINE. This syndrome is caused by mutations of gene THRB encoding the THYROID HORMONE RECEPTORS BETA in target cells. HYPOTHYROIDISM in these patients is partly overcome by the increased thyroid hormone levels.
Transcription, Genetic
Gene Expression Regulation
Thyroid Neoplasms
Tumors or cancer of the THYROID GLAND.
Protein Isoforms
Nuclear Receptor Co-Repressor 2
A nuclear co-repressor protein that shows specificity for RETINOIC ACID RECEPTORS and THYROID HORMONE RECEPTORS. The dissociation of this co-repressor from nuclear receptors is generally ligand-dependent, but can also occur by way of its phosphorylation by members of the MAP KINASE SIGNALING SYSTEM. The protein contains two nuclear receptor interaction domains and four repressor domains and is closely-related in structure to NUCLEAR RECEPTOR CO-REPRESSOR 1.
RNA, Messenger
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Receptors, Retinoic Acid
Estrogen Receptor alpha
Thyroid Diseases
Pathological processes involving the THYROID GLAND.
Nuclear Receptor Co-Repressor 1
A nuclear protein that regulates the expression of genes involved in a diverse array of processes related to metabolism and reproduction. The protein contains three nuclear receptor interaction domains and three repressor domains and is closely-related in structure to NUCLEAR RECEPTOR CO-REPRESSOR 2.
Iodide Peroxidase
Thyrotropin
A glycoprotein hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Thyrotropin stimulates THYROID GLAND by increasing the iodide transport, synthesis and release of thyroid hormones (THYROXINE and TRIIODOTHYRONINE). Thyrotropin consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the pituitary glycoprotein hormones (TSH; LUTEINIZING HORMONE and FSH), but the beta subunit is unique and confers its biological specificity.
Metamorphosis, Biological
Genes, erbA
Genes related to the erbA DNA sequence that was first isolated from the avian erythroblastosis virus (ERYTHROBLASTOSIS VIRUS, AVIAN), v-erbA. In cells, erbA genes encode thyroid hormone receptors (RECEPTORS, THYROID HORMONE). Two distinct c-erbA genes have been identified: erbA-alpha located at 17q21; and erbA-beta located at 3p24. Truncations at the N- and C-terminals of erbA result in products resembling v-erbA. Truncations affect hormone responsiveness but not DNA binding capacity.
Transcription Factors
Hyperthyroidism
Hypersecretion of THYROID HORMONES from the THYROID GLAND. Elevated levels of thyroid hormones increase BASAL METABOLIC RATE.
Triiodothyronine, Reverse
A metabolite of THYROXINE, formed by the peripheral enzymatic monodeiodination of T4 at the 5 position of the inner ring of the iodothyronine nucleus.
Thyroid Function Tests
Blood tests used to evaluate the functioning of the thyroid gland.