In the field of

molecular biology Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physi ...

, the ETS (E26 transformation-specific or E-twenty-six. (Erythroblast Transformation Specific)) family is one of the largest families of

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 fun ...

and is unique to

animals Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...

. There are 29 genes in humans, 28 in the mouse, 10 in '' Caenorhabditis elegans'' and 9 in ''

Drosophila ''Drosophila'' () is a genus of flies, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or (less frequently) pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many speci ...

.'' The founding member of this family was identified as a gene transduced by the leukemia virus, E26. The members of the family have been implicated in the development of different tissues as well as cancer progression.

Subfamilies

The ETS (Erythroblast Transformation Specific)family is divided into 12 subfamilies, which are listed below:

Structure

All ETS (Erythroblast Transformation Specific) family members are identified through a highly conserved DNA binding domain, the ETS domain, which is a winged

helix-turn-helix Helix-turn-helix is a DNA-binding protein (DBP). The helix-turn-helix (HTH) is a major structural motif capable of binding DNA. Each monomer incorporates two α helices, joined by a short strand of amino acids, that bind to the major groove of ...

structure that binds to DNA sites with a central GGA(A/T) DNA sequence. As well as DNA-binding functions, evidence suggests that the ETS domain is also involved in protein-protein interactions. There is limited similarity outside the ETS DNA binding domain. Other domains are also present and vary from ETS member to ETS member, including the Pointed domain, a subclass of the SAM domain family.

Function

The ETS family is present throughout the body and is involved in a wide variety of functions including the regulation of cellular differentiation,

cell cycle The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and sub ...

control,

cell migration Cell migration is a central process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular dire ...

, cell proliferation, apoptosis (programmed cell death) and angiogenesis. Multiple ETS factors have been found to be associated with cancer, such as through gene fusion. For example, the ERG ETS transcription factor is fused to the EWS gene, resulting in a condition called

Ewing's sarcoma Ewing sarcoma is a type of cancer that forms in bone or soft tissue. Symptoms may include swelling and pain at the site of the tumor, fever, and a bone fracture. The most common areas where it begins are the legs, pelvis, and chest wall. In about ...

. The fusion of TEL to the

JAK2 Janus kinase 2 (commonly called JAK2) is a non-receptor tyrosine kinase. It is a member of the Janus kinase family and has been implicated in signaling by members of the type II cytokine receptor family (e.g. interferon receptors), the GM-CSF rece ...

protein results in early pre-B acute lymphoid leukaemia. ERG and ETV1 are known gene fusions found in prostate cancer. In addition, ETS factors, e.g. the vertebrate Etv1 and the invertebrate Ast-1, have been shown to be important players in the specification and differentiation of dopaminergic neurons in both '' C. elegans'' and olfactory bulbs of mice.

Mode of action

Amongst members of the ETS family, there is extensive conservation in the DNA-binding ETS domain and, therefore, a lot of redundancy in DNA binding. It is thought that interactions with other proteins (eg: Modulator of the activity of Ets called Mae) is one way in which specific binding to DNA is achieved. Transcription factor Ets are a site of signalling convergence. ETS factors act as transcriptional repressors,

transcriptional activators A transcriptional activator is a protein (transcription factor) that increases transcription of a gene or set of genes. Activators are considered to have ''positive'' control over gene expression, as they function to promote gene transcription and ...

, or both.

Subfamilies

Structure

Function

Mode of action

References

Further reading