Evolutionary changes to transthyretin: developmentally regulated and tissue-specific gene expression

Kiyoshi Yamauchi1, Akinori Ishihara

  • 1Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka, Japan. sbkyama@ipc.shizuoka.ac.jp

The FEBS Journal
|September 4, 2009
PubMed

A survey of the expression of the transthyretin and thyroxine-binding globulin genes in various species during development provides clues as to how the present thyroid hormone distribution network in extracellular compartments developed during vertebrate evolution. Albumin may be the 'oldest' component of the thyroid hormone distribution network as it is found in the plasma of all vertebrates investigated. Subsequent to albumin, transthyretin appeared as the second component in this network during the evolution of vertebrates. The strong expression of transthyretin genes in the liver coincides with the presence of recognition site(s) for liver-enriched transcription factors, such as HNF-3beta (Foxa2), in the transthyretin promoter regions of vertebrates. Finally, the addition of thyroxine-binding globulin to this network occurred at postnatal stages in some marsupials and rodents and in perinatal to adult stages in most eutherians. All vertebrates have defined developmental stages when thyroid hormone-dependent transition from larval to juvenile forms occurs. The inclusion of transthyretin and thyroxine-binding globulin in the thyroid hormone distribution network may be correlated with the increased requirement of thyroid hormones for thyroid hormone-dependent tissue remodeling during these stages and/or increased metabolism in thyroid hormone-target tissues with the acquisition of homeothermy.

Related Concept Videos

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase01:11

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase

Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
General Transcription Factors01:30

General Transcription Factors

Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
Regulation of Expression at Multiple Steps01:23

Regulation of Expression at Multiple Steps

The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a...
Transcription Factors02:16

Transcription Factors

Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
What is Gene Expression?01:36

What is Gene Expression?

A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised  of nucleotides and proteins are comprised of amino acids, a mediator is required to convert the information encoded in DNA into proteins. This mediator is the messenger RNA (mRNA). mRNA copies the blueprint from DNA by a process called transcription. In eukaryotes, transcription occurs in the nucleus by complementary base-pairing with the DNA template. The mRNA is then processed and...
What is Gene Expression?01:42

What is Gene Expression?

Overview
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...