Paired box gene 8, also known as PAX8, is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 which in humans is encoded by the PAX8 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

Function

This gene is a member of the paired box (PAX

Pax genes

Paired box genes are a family of tissue specific transcription factors containing a paired domain and usually a partial or complete homeodomain. An octapeptide may also be present...

) family of transcription factor

Transcription factor

In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...

s. Members of this gene family typically encode proteins which contain a paired box domain, an octapeptide, and a paired-type homeodomain

Homeodomain fold

The homeodomain fold is a protein structural domain that binds DNA or RNA and is thus commonly found in transcription factors. The fold consists of a 60-amino acid helix-turn-helix structure in which three alpha helices are connected by short loop regions...

. This nuclear protein is involved in thyroid follicular cell

Thyroid epithelial cell

Thyroid epithelial cells are cells in the thyroid gland that are responsible for the production and secretion of thyroid hormones, that is, thyroxine and triiodothyronine .-Function:...

 development and expression of thyroid-specific genes. Also functions in very early stages of kidney organogenesis.

Clinical significance

Mutations in this gene have been associated with thyroid dysgenesis

Thyroid dysgenesis

Thyroid agenesis is a cause of congenital hypothyroidism where the thyroid is missing, ectopic, or severely underdeveloped....

, thyroid follicular carcinoma

Follicular thyroid cancer

Follicular thyroid cancer accounts for 15% of thyroid cancer which occurs more commonly in women of over 50 years old. Thyroglobulin can be used as a tumor marker for well-differentiated follicular thyroid cancer.-Classification:...

s and atypical follicular thyroid adenoma

Thyroid adenoma

-Types:Almost all thyroid adenomas are follicular adenomas. Follicular adenomas can be described as "cold", "warm" or "hot" depending on their level of function...

s. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.

Interactions

PAX8 has been shown to interact

Protein-protein interaction

Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...

 with NK2 homeobox 1.

Further reading