''SOX'' genes (''
SRY''-related
HMG-box genes) encode a family of
transcription factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription (genetics), transcription of genetics, genetic information from DNA to messenger RNA, by binding t ...
s that bind to the
minor groove in
DNA
Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
, and belong to a super-family of
genes
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
characterized by a
homologous sequence called the HMG-box (for
high mobility group). This HMG box is a
DNA binding domain that is highly conserved throughout
eukaryotic
The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms ...
species.
Homologues have been identified in insects, nematodes, amphibians, reptiles, birds and a range of mammals. However, HMG boxes can be very diverse in nature, with only a few
amino acids
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the Proteinogenic amino acid, 22 α-amino acids incorporated into p ...
being conserved between species.
Sox genes are defined as containing the HMG box of a gene involved in sex determination called ''
SRY'', which resides on the
Y-chromosome. There are 20 SOX genes present in humans and mice, and 8 present in Drosophila. Almost all Sox genes show at least 50% amino acid similarity with the HMG box in Sry. The family is divided into subgroups according to homology within the HMG domain and other structural motifs, as well as according to functional assays.
The developmentally important Sox family has no singular function, and many members possess the ability to regulate several different aspects of development. While many Sox genes are involved in sex determination, some are also important in processes such as
neuronal
A neuron (American English), neurone (British English), or nerve cell, is an excitable cell that fires electric signals called action potentials across a neural network in the nervous system. They are located in the nervous system and help to ...
development. For example, Sox2 and Sox3 are involved in the transition of epithelial granule cells in the cerebellum to their migratory state. Sox 2 is also a transcription factor in the maintenance of pluripotency in both Early Embryos and ES Cells. Granule cells then differentiate to granule neurons, with Sox11 being involved in this process. It is thought that some Sox genes may be useful in the early diagnosis of childhood
brain tumour
A brain tumor (sometimes referred to as brain cancer) occurs when a group of cells within the brain turn cancerous and grow out of control, creating a mass. There are two main types of tumors: malignant (cancerous) tumors and benign (non-cancero ...
s due to this sequential expression in the cerebellum, making them a target for significant research.
Sox proteins bind to the sequence WWCAAW and similar sequences (
W=A or T). They have weak binding specificity and unusually low affinity for DNA. Sox genes are related to the
Tcf/Lef1 group of genes which also contain a sequence-specific high mobility group and have a similar sequence specificity (roughly TWWCAAAG).
Groups
Sox genes are classified into groups. Sox genes from different groups share little similarity outside the DNA-binding domain. In mouse and human the members of the groups are:
* SoxA: ''
SRY''
* SoxB1: ''
SOX1'', ''
SOX2'', ''
SOX3''
* SoxB2: ''
SOX14'', ''
SOX21
Transcription factor SOX-21 is a protein that in humans is encoded by the ''SOX21'' gene. It is a member of the SOX genes, Sox gene family of transcription factors.
Function
In the chick embryo, Sox21 promotes neuronal cellular cellular differ ...
''
* SoxC: ''
SOX4'', ''
SOX11,'' ''
SOX12''
* SoxD: ''
SOX5'', ''
SOX6'', ''
SOX13''
* SoxE: ''
SOX8'', ''
SOX9
Transcription factor SOX-9 is a protein that in humans is encoded by the ''SOX9'' gene.
Function
SOX-9 recognizes the sequence CCTTGAG along with other members of the HMG-box class DNA-binding domain, DNA-binding proteins. It is expressed by ...
'', ''
SOX10
Transcription factor SOX-10 is a protein that in humans is encoded by the ''SOX10'' gene.
Function
This gene encodes a member of the SOX gene family, SOX (Testis-determining factor, SRY-related HMG-box) family of transcription factors involved ...
''
* SoxF: ''
SOX7'', ''
SOX17'', ''
SOX18''
* SoxG: ''
SOX15''
* SoxH: ''
SOX30''
See also
*
Body plan
A body plan, (), or ground plan is a set of morphology (biology), morphological phenotypic trait, features common to many members of a phylum of animals. The vertebrates share one body plan, while invertebrates have many.
This term, usually app ...
*
Evolutionary developmental biology
Evolutionary developmental biology, informally known as evo-devo, is a field of biological research that compares the developmental biology, developmental processes of different organisms to infer how developmental processes evolution, evolved. ...
*
FOX proteins
FOX (forkhead box) proteins are a family of transcription factors that play important roles in regulating the expression of genes involved in cell growth, proliferation, Cellular differentiation, differentiation, and longevity. Many FOX proteins a ...
*
Hox gene
Hox genes, a subset of homeobox, homeobox genes, are a gene cluster, group of related genes that Evolutionary developmental biology, specify regions of the body plan of an embryo along the craniocaudal axis, head-tail axis of animals. Hox protein ...
*
Pax genes
In evolutionary developmental biology, Paired box (Pax) genes are a family of genes coding for tissue specific transcription factors containing an N-terminal paired domain and usually a partial, or in the case of four family members (PAX3, PAX4, P ...
References
*
*
External links
* NCBI CDD
cd01388(SOX-TCF_HMG-box)
human proteins
{{Transcription factors, g4
Gene families
Transcription factors