scholarly journals Prokaryotic Solute/Sodium Symporters: Versatile Functions and Mechanisms of a Transporter Family

2021 ◽  
Vol 22 (4) ◽  
pp. 1880
Author(s):  
Tania Henriquez ◽  
Larissa Wirtz ◽  
Dan Su ◽  
Heinrich Jung
Keyword(s):  
Glucose Transporter ◽  
Large Family ◽  
Sodium Iodide Symporter ◽  
Host Interactions ◽  
Iodide Transport ◽  
Transporter Family ◽  
Sodium Gradient ◽  
Sensor Kinases ◽  
Transport Defect ◽  
Functional Features

The solute/sodium symporter family (SSS family; TC 2.A.21; SLC5) consists of integral membrane proteins that use an existing sodium gradient to drive the uphill transport of various solutes, such as sugars, amino acids, vitamins, or ions across the membrane. This large family has representatives in all three kingdoms of life. The human sodium/iodide symporter (NIS) and the sodium/glucose transporter (SGLT1) are involved in diseases such as iodide transport defect or glucose-galactose malabsorption. Moreover, the bacterial sodium/proline symporter PutP and the sodium/sialic acid symporter SiaT play important roles in bacteria–host interactions. This review focuses on the physiological significance and structural and functional features of prokaryotic members of the SSS family. Special emphasis will be given to the roles and properties of proteins containing an SSS family domain fused to domains typically found in bacterial sensor kinases.

scholarly journals Congenital Hypothyroidism Caused by a PAX8 Gene Mutation Manifested as Sodium/Iodide Symporter Gene Defect

2010 ◽  
Vol 2010 ◽  
pp. 1-3 ◽  
Author(s):  
Wakako Jo ◽  
Katsura Ishizu ◽  
Kenji Fujieda ◽  
Toshihiro Tajima
Keyword(s):  
Thyroid Gland ◽  
Congenital Hypothyroidism ◽  
Sodium Iodide ◽  
Present Report ◽  
Sodium Iodide Symporter ◽  
Loss Of Function ◽  
Laboratory Findings ◽  
Iodide Transport ◽  
Transport Defect ◽  
Pax8 Gene

Loss-of-function mutations of the PAX8 gene are considered to mainly cause congenital hypothyroidism (CH) due to thyroid hypoplasia. However, some patients with PAX8 mutation have demonstrated a normal-sized thyroid gland. Here we report a CH patient caused by a PAX8 mutation, which manifested as iodide transport defect (ITD). Hypothyroidism was detected by neonatal screening and L-thyroxine replacement was started immediately. Although I scintigraphy at 5 years of age showed that the thyroid gland was in the normal position and of small size, his iodide trapping was low. The ratio of the saliva/plasma radioactive iodide was low. He did not have goiter; however laboratory findings suggested that he had partial ITD. Gene analyses showed that the sodium/iodide symporter (NIS) gene was normal; instead, a mutation in the PAX8 gene causing R31H substitution was identified. The present report demonstrates that individuals with defective PAX8 can have partial ITD, and thus genetic analysis is useful for differential diagnosis.

A Novel V59E Missense Mutation in the Sodium Iodide Symporter Gene in a Family with Iodide Transport Defect

Thyroid ◽  
2000 ◽  
Vol 10 (6) ◽  
pp. 471-474 ◽  
Author(s):  
Hirokazu Fujiwara ◽  
Ke-ita Tatsumi ◽  
Susumu Tanaka ◽  
Masahiro Kimura ◽  
Osamu Nose ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Sodium Iodide ◽  
Sodium Iodide Symporter ◽  
Iodide Transport ◽  
Transport Defect

scholarly journals Molecular Analysis of the Sodium/Iodide Symporter: Impact on Thyroid and Extrathyroid Pathophysiology

2000 ◽  
Vol 80 (3) ◽  
pp. 1083-1105 ◽  
Author(s):  
Antonio De la Vieja ◽  
Orsolya Dohan ◽  
Orlie Levy ◽  
Nancy Carrasco
Keyword(s):  
Thyroid Cancer ◽  
Molecular Analysis ◽  
Posttranslational Modifications ◽  
Wide Spectrum ◽  
Sodium Iodide Symporter ◽  
Iodide Transport ◽  
Thyroid Hormone Biosynthesis ◽  
Lactating Mammary Gland ◽  
Transport Defect ◽  
Radioiodide Therapy

The Na+/I−symporter (NIS) is an intrinsic membrane protein that mediates the active transport of iodide into the thyroid and other tissues, such as salivary glands, gastric mucosa, and lactating mammary gland. NIS plays key roles in thyroid pathophysiology as the route by which iodide reaches the gland for thyroid hormone biosynthesis and as a means for diagnostic scintigraphic imaging and for radioiodide therapy in hyperthyroidism and thyroid cancer. The molecular characterization of NIS started with the 1996 isolation of a cDNA encoding rat NIS and has since continued at a rapid pace. Anti-NIS antibodies have been prepared and used to study NIS topology and its secondary structure. The biogenesis and posttranslational modifications of NIS have been examined, a thorough electrophysiological analysis of NIS has been conducted, the cDNA encoding human NIS (hNIS) has been isolated, the genomic organization of hNIS has been elucidated, the regulation of NIS by thyrotropin and I− has been analyzed, the regulation of NIS transcription has been studied, spontaneous NIS mutations have been identified as causes of congenital iodide transport defect resulting in hypothyroidism, the roles of NIS in thyroid cancer and thyroid autoimmune disease have been examined, and the expression and regulation of NIS in extrathyroidal tissues have been investigated. In gene therapy experiments, the rat NIS gene has been transduced into various types of human cells, which then exhibited active iodide transport and became susceptible to destruction with radioiodide. The continued molecular analysis of NIS clearly holds the potential of an even greater impact on a wide spectrum of fields, ranging from structure/function of transport proteins to the diagnosis and treatment of cancer, both in the thyroid and beyond.

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