''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 of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The f ...

s that bind to the minor groove in DNA, and belong to a super-family of

genes In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

characterized by a homologous sequence called the HMG-box (for high mobility group). This HMG box is a

DNA binding domain A DNA-binding domain (DBD) is an independently folded protein domain that contains at least one structural motif that recognizes double- or single-stranded DNA. A DBD can recognize a specific DNA sequence (a recognition sequence) or have a genera ...

that is highly conserved throughout

eukaryotic Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...

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 hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

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 The Y chromosome is one of two sex chromosomes ( allosomes) in therian mammals, including humans, and many other animals. The other is the X chromosome. Y is normally the sex-determining chromosome in many species, since it is the presence or ...

. 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 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 occurs when abnormal cells form within the brain. There are two main types of tumors: malignant tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and second ...

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 Transcription factor SOX-3 is a protein that in humans is encoded by the ''SOX3'' gene. This gene encodes a member of the SOX (SRY-related HMG-box) family of transcription factors involved in the regulation of embryonic brain development and i ...

'' * SoxB2: '' SOX14'', '' SOX21'' * SoxC: '' SOX4'', '' SOX11,'' '' SOX12'' * SoxD: ''

SOX5 Transcription factor SOX-5 is a protein that in humans is encoded by the ''SOX5'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' o ...

'', ''

SOX6 Transcription factor SOX-6 is a protein that in humans is encoded by the ''SOX6'' gene. Function The SOX gene family encodes a group of transcription factors defined by the conserved high mobility group (HMG) DNA-binding domain. Unlike most tr ...

'', '' 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 proteins. It is expressed by proliferating but n ...

'', '' SOX10'' * SoxF: '' SOX7'', '' SOX17'', ''

SOX18 Transcription factor SOX-18 is a protein that in humans is encoded by the ''SOX18'' gene. Function This gene encodes a member of the SOX (SRY-related HMG-box) family of transcription factors involved in the regulation of embryonic developmen ...

'' * SoxG: '' SOX15'' * SoxH: ''

SOX30 SRY (sex determining region Y)-box 30 is a protein that in humans is encoded by the SOX30 gene. Function This gene encodes a member of the SOX (SRY-related HMG-box) family of transcription factors involved in the regulation of embryonic devel ...

References

* *

External links

* NCBI CDD
cd01388
(SOX-TCF_HMG-box)
human proteins
{{Transcription factors, g4 Gene families Transcription factors

Groups

See also

References

External links