The Na(+)/I(-) symporter (NIS) is an integral plasma membrane glycoprotein that mediates active I(-) transport into the thyroid follicular cells, the first step in thyroid hormone biosynthesis. NIS-mediated thyroidal I(-) transport from the bloodstream to the colloid is a vectorial process made possible by the selective targeting of NIS to the basolateral membrane. NIS also mediates active I(-) transport in other tissues, including salivary glands, gastric mucosa, and lactating mammary gland, in which it translocates I(-) into the milk for thyroid hormone biosynthesis by the nursing newborn. NIS provides the basis for the effective diagnostic and therapeutic management of thyroid cancer and its metastases with radioiodide. NIS research has proceeded at an astounding pace after the 1996 isolation of the rat NIS cDNA, comprising the elucidation of NIS secondary structure and topology, biogenesis and posttranslational modifications, transcriptional and posttranscriptional regulation, electrophysiological analysis, isolation of the human NIS cDNA, and determination of the human NIS genomic organization. Clinically related topics include the analysis of congenital I(-) transport defect-causing NIS mutations and the role of NIS in thyroid cancer. NIS has been transduced into various kinds of cancer cells to render them susceptible to destruction with radioiodide. Most dramatically, the discovery of endogenous NIS expression in more than 80% of human breast cancer samples has raised the possibility that radioiodide may be a valuable novel tool in breast cancer diagnosis and treatment.

The sodium/iodide Symporter (NIS): characterization, regulation, and medical significance.

Coenzyme A: back in action.

The sodium/glucose cotransporter family (SLCA5) has 220 or more members in animal and bacterial cells. There are 11 human genes expressed in tissues ranging from epithelia to the central nervous system. The functions of nine have been revealed by studies using heterologous expression systems: six are tightly coupled plasma membrane Na+/substrate cotransporters for solutes such as glucose, myo-inositol and iodide; one is a Na+/Cl−/choline cotransporter; one is an anion transporter; and another is a glucose-activated ion channel. The exon organization of eight genes is similar in that each comprises 14–15 exons. The choline transporter (CHT) is encoded in eight exons and the Na+-dependent myo-inositol transporter (SMIT) in one exon. Mutations in three genes produce genetic diseases (glucose-galactose malabsorption, renal glycosuria and hypothyroidism). Members of this family are multifunctional membrane proteins in that they also behave as uniporters, urea and water channels, and urea and water cotransporters. Consequently it is a challenge to determine the role(s) of these genes in human physiology and pathology.

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The sodium/glucose cotransport family SLC5.

The ABCs of membrane transporters in health and disease (SLC series): Introduction

https://www.jstage.jst.go.jp/article/dmpk/20/6/20_6_452/_pdf

Vadivel Ganapathy

Papers

Human Placental Na+-dependent Multivitamin Transporter: CLONING, FUNCTIONAL EXPRESSION, GENE STRUCTURE, AND CHROMOSOMAL LOCALIZATION

Assignment of the human folate transporter gene to chromosome 21q22.3 by somatic cell hybrid analysis and in situ hybridization.

TRANSPORT OF WATER-SOLUBLE VITAMINS - A Review -