SOX genes
Encyclopedia
SOX genes encode a family of transcription factor
s that bind to the minor groove in DNA
, and belong to a super-family of genes
characterized by a homologous
sequence called the HMG (high mobility group
) box. This HMG box is a DNA binding domain that is highly conserved throughout eukaryotic
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 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 (Sox stands for Sry-related HMG box). 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. 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 tumours 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/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).
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 that bind to the minor groove in DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
, and belong to a super-family of genes
Gênes
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...
characterized by a homologous
Homology (biology)
Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
sequence called the HMG (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:...
) box. This HMG box is a DNA binding domain that is highly conserved throughout eukaryotic
Eukaryote
A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
species. Homologues
Homology (biology)
Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
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 being conserved between species.
Sox genes are defined as containing the HMG box of a gene involved in sex determination called SRY
SRY
SRY is a sex-determining gene on the Y chromosome in the therians .This intronless gene encodes a transcription factor that is a member of the SOX gene family of DNA-binding proteins...
, which resides on the Y-chromosome (Sox stands for Sry-related HMG box). 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. 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 tumours 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/T
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
). They have weak binding specificity and unusually low affinity for DNA. Sox genes are related to the Tcf/Lef1
TCF/LEF family
The TCF/LEF family is a group of transcription factors which bind to DNA through a high mobility group domain. They are involved in the Wnt signaling pathway, where they recruit the coactivator beta-catenin to enhancer elements of genes they target. They can also recruit members of the Groucho...
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: SRYSRYSRY is a sex-determining gene on the Y chromosome in the therians .This intronless gene encodes a transcription factor that is a member of the SOX gene family of DNA-binding proteins...
- SoxB1: SOX1SOX1SOX1 is a transcription factor in the Sox protein family. SOX1 expression is restricted to neuroectoderm in the tetrapod embryo. SOX1 is involved in early central nervous system development, where it is functionally redundant with SOX3 and to a lesser degree SOX2, and maintenance of neural...
, SOX2SOX2SRY -box 2, also known as SOX2, is a transcription factor that is essential to maintain self-renewal of undifferentiated embryonic stem cells....
, SOX3SOX3Transcription factor SOX-3 is a protein that in humans is encoded by the SOX3 gene.This gene encodes a member of the SOX family of transcription factors involved in the regulation of embryonic brain development and in determination of cell fate. The encoded protein acts as a transcriptional... - SoxB2: SOX14SOX14Transcription factor SOX-14 is a protein that in humans is encoded by the SOX14 gene.-Further reading:...
, SOX21SOX21Transcription factor SOX-21 is a protein that in humans is encoded by the SOX21 gene. It is a member of the Sox gene family of transcription factors.- Function :... - SoxC: SOX4SOX4Transcription factor SOX-4 is a protein that in humans is encoded by the SOX4 gene.Sox4 is expressed in lymphocytes and is required for B lymphocyte development....
, SOX11SOX11Transcription factor SOX-11 is a protein that in humans is encoded by the SOX11 gene. Tuj1 and Tead2 are suggested as direct target of Sox11.-Further reading:...
, SOX12SOX12SOX12 is a protein that in humans is encoded by the SOX12 gene. Sox12 belongs to the SoxC group of Sox family of transcription factors, together with Sox4 and Sox11. Sox12-null knockout mice appear normal, unlike Sox4 or Sox11 knockout mice. This probably comes from functional redundancy with Sox4... - SoxD: SOX5SOX5Transcription factor SOX-5 is a protein that in humans is encoded by the SOX5 gene.-Further reading:...
, SOX6SOX6Transcription factor SOX-6 is a protein that in humans is encoded by the SOX6 gene.-Interactions:SOX6 has been shown to interact with CTBP2 and CENPK....
, SOX13SOX13Transcription factor SOX-13 is a protein that in humans is encoded by the SOX13 gene.-Further reading:... - SoxE: SOX8SOX8Transcription factor SOX-8 is a protein that in humans is encoded by the SOX8 gene.-Further reading:...
, SOX9SOX9Transcription 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...
, SOX10SOX10Transcription factor SOX-10 is a protein that in humans is encoded by the SOX10 gene.... - SoxF: SOX7, SOX17, SOX18SOX18Transcription factor SOX-18 is a protein that in humans is encoded by the SOX18 gene....
- SoxG: SOX15SOX15Protein SOX-15 is a protein that in humans is encoded by the SOX15 gene.-Further reading:...
- SoxH: SOX30