SoxC group is group C of Sry-related HMG box proteins

transcription factors 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 ...

. SoxC genes play an important role in determining the cell fate of neuronal mesenchymal progenitor cells in many developmental processes.Huang, J. et al. The transcription factor sry-related HMG box-4 (SOX4) is required for normal renal development in vivo. ''Dev. Dynamics'' 2013, ''242,'' no p.n

/ref> In ''

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (the taxonomic order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the " vinegar fly" or " pomace fly". Starting with ...

'' (fly), ''

Caenorhabditis elegans ''Caenorhabditis elegans'' () is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek ''caeno-'' (recent), ''rhabditis'' (r ...

'' (worm), and other lower animals SoxC is made up of only one member, but humans, mice and most other vertebrates have three members of the SoxC group.Dy, P. et al. The three SoxC proteins–Sox4, Sox11 and Sox12–exhibit overlapping expression patterns and molecular properties. ''Nucleic Acids Research'' 2008, ''36'', 3101–311

/ref> The three are Sox4, Sox11, and Sox12. These three are extremely similar to one another, more so than other proteins, but they are all highly distinct in the way that they bind DNA and active Transcription (genetics), transcription ''in vitro'' with different affinity.Penzo-Méndez, A. I. Critical roles for SoxC transcription factors in development and cancer. ''The Int. Jour. of Biochem. & Cell Bio.'', 2010, ''42'', 425-42

/ref> The three found in humans and other vertebrates are single-

exon An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequenc ...

genes. The SoxC proteins have 2 domains, the first an Sry-related HMG box DNA binding domain that is located near the

N-terminal The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amin ...

and the second a trans-activation domain, known as TAD, located near the

C-terminal The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is ...

. Although these are transcription factors, to this date there is no evidence of

post-translational modification Post-translational modification (PTM) is the covalent and generally enzymatic modification of proteins following protein biosynthesis. This process occurs in the endoplasmic reticulum and the golgi apparatus. Proteins are synthesized by ribos ...

s on SoxC members, but they can work cooperatively with other proteins though, such as transcription factors Brn2 and Brn1. All of the SoxC proteins share 67% identity and 94% similarity in the 33 residues of the C-terminal domain. All SoxC genes show 84% identity and 95% similarity to one another in the HMG box, which is just slightly more highly conserved than the C-terminal domain. The SoxC proteins only have between 45% to 67% identity to Sry and the other Sox proteins. The SoxC genes found in the ''Drosophila melanogaster'' (fly), ''Caenorhabditis elegans'' (worm), and other lower animals are closely linked to those found in humans and other vertebrates. The SoxC genes are highly conserved through vertebrate evolution and are similar enough to those in invertebrates and other lower animal species to speculate that these are based on an evolutionary necessity from before vertebrates and invertebrates separated through evolution. If these SoxC proteins were missing during developmental stages it would cause widespread problems through the body of mice, and in many cases death. These have not been studied in humans though, because no occurrences have been linked to congential malformations of any of these proteins. In mice however, mice embryos without Sox4 die of heart defects, but mice newborns without Sox11 do live but have widespread defects. Mice without Sox12 are viable and show no outward signs of malformation. Some of the common human

malformations A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can r ...

are also seen in mice with mutated SoxC, such as

cleft palate A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nose. The t ...

or heart outflow tract malformation. There is no evidence of the correlation between SoxC mutations in humans and these malformations, but there is speculation. Sox4 facilitates differentiation of lymphocytes,

osteoblasts Osteoblasts (from the Greek combining forms for "bone", ὀστέο-, ''osteo-'' and βλαστάνω, ''blastanō'' "germinate") are cells with a single nucleus that synthesize bone. However, in the process of bone formation, osteoblasts function ...

, pancreatic

beta cells Beta cells (β-cells) are a type of cell found in pancreatic islets that synthesize and secrete insulin and amylin. Beta cells make up 50–70% of the cells in human islets. In patients with Type 1 diabetes, beta-cell mass and function are dim ...

and along with Sox11 promotes neural

differentiation Differentiation may refer to: Business * Differentiation (economics), the process of making a product different from other similar products * Product differentiation, in marketing * Differentiated service, a service that varies with the identity ...

. In recent years, the belief has raised that SoxC genes may lead to tumor prognosis at elevated levels. Increased expression of Sox11 and Sox4 are seen in numerous tumors and cancers and it is possible that the tumors differ depending on the circumstance and primary transformation mechanism.

References

{{reflist Genetics