TOX
Encyclopedia
Thymocyte selection-associated high mobility group box protein TOX is a protein
that in humans is encoded by the TOX gene
.
that belongs to a large superfamily of chromatin
associated proteins that share an approximately 75 amino acid DNA binding motif
, the HMG (high mobility group)-box
(named after that found in the canonical member of the family, high mobility group protein 1). Some high mobility group
(HMG) box proteins (e.g., LEF1) contain a single HMG box motif and bind DNA in a sequence-specific manner, while other members of this family (e.g., HMGB1
) have multiple HMG boxes and bind DNA in a sequence-independent but structure-dependent manner. While TOX has a single HMG-box motif, it is predicted to bind DNA in a sequence-independent manner.. TOX is also a member of a small subfamily of proteins (TOX2
, TOX3
, and TOX4
) that share almost identical HMG-box sequences. TOX3 has been identified as a breast cancer susceptibility locus. TOX is highly expressed in the thymus
, the site of development of T lymphocytes. Knockout mice
that lack TOX have a severe defect in development of certain subsets of T lymphocytes.
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...
that in humans is encoded by the TOX 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...
.
Structure and function
The TOX gene encodes a proteinProtein
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...
that belongs to a large superfamily of chromatin
Chromatin
Chromatin is the combination of DNA and proteins that make up the contents of the nucleus of a cell. The primary functions of chromatin are; to package DNA into a smaller volume to fit in the cell, to strengthen the DNA to allow mitosis and meiosis and prevent DNA damage, and to control gene...
associated proteins that share an approximately 75 amino acid DNA binding motif
DNA-binding domain
A DNA-binding domain is an independently folded protein domain that contains at least one motif that recognizes double- or single-stranded DNA. A DBD can recognize a specific DNA sequence or have a general affinity to DNA...
, the HMG (high mobility group)-box
HMG-box
The HMG-box is a protein domain which is involved in DNA binding.-Structure:The structure of the HMG-box domain contains three alpha helices separated by loops .-Function:...
(named after that found in the canonical member of the family, high mobility group protein 1). Some high mobility group
High mobility group
High-Mobility Group or HMG is a group of chromosomal proteins that help withtranscription, replication, recombination, and DNA repair.-Families:The HMG proteins are subdivided into 3 superfamilies each containing a characteristic functional domain:...
(HMG) box proteins (e.g., LEF1) contain a single HMG box motif and bind DNA in a sequence-specific manner, while other members of this family (e.g., HMGB1
HMGB1
High-mobility group protein B1, also known as high-mobility group protein 1 and amphoterin, is a protein that in humans is encoded by the HMGB1 gene.HMG-1 belongs to high mobility group.-Role in Inflammation:...
) have multiple HMG boxes and bind DNA in a sequence-independent but structure-dependent manner. While TOX has a single HMG-box motif, it is predicted to bind DNA in a sequence-independent manner.. TOX is also a member of a small subfamily of proteins (TOX2
TOX2
TOX high mobility group box family member 2, also known as TOX2, is a human gene.The protein encoded by this gene is a member of a subfamily of transcription factors that also includes TOX, TOX3, and TOX4 that share almost identical HMG-box DNA-binding domains which function to modify chromatin...
, TOX3
TOX3
TOX high mobility group box family member 3, also known as TOX3, is a human gene.The protein encoded by this gene is a member of a subfamily of transcription factors that also includes TOX, TOX2, and TOX4 that share almost identical HMG-box DNA-binding domains which function to modify chromatin...
, and TOX4
TOX4
TOX4 also known as KIAA0737, is a human gene.-Further reading:...
) that share almost identical HMG-box sequences. TOX3 has been identified as a breast cancer susceptibility locus. TOX is highly expressed in the thymus
Thymus
The thymus is a specialized organ of the immune system. The thymus produces and "educates" T-lymphocytes , which are critical cells of the adaptive immune system....
, the site of development of T lymphocytes. Knockout mice
Knockout mouse
A knockout mouse is a genetically engineered mouse in which researchers have inactivated, or "knocked out," an existing gene by replacing it or disrupting it with an artificial piece of DNA...
that lack TOX have a severe defect in development of certain subsets of T lymphocytes.