ELF5

ELF5

The structure of ELF5 protein.

ELF5 (E74-like factor 5) is a transcription factor that plays a crucial role in mammalian development and tissue differentiation. It belongs to the ETS (E26 transformation-specific) family of transcription factors and is encoded by the ELF5 gene located on human chromosome 11q23.1.

Structure

ELF5 consists of several functional domains that contribute to its transcriptional activity. It contains an N-terminal ETS DNA-binding domain, which recognizes specific DNA sequences known as ETS-binding sites. This domain allows ELF5 to bind to target gene promoters and regulate their expression. Additionally, ELF5 possesses a C-terminal transactivation domain that interacts with other transcriptional co-factors to activate or repress gene transcription.

Function

ELF5 is primarily known for its role in mammary gland development and lactation. During pregnancy, ELF5 is highly expressed in the mammary epithelial cells and is essential for the formation of alveolar structures, which are responsible for milk production. It promotes the differentiation of mammary epithelial cells into secretory alveolar cells and inhibits their proliferation, ensuring proper milk production and secretion.

Furthermore, ELF5 has been implicated in the development of other tissues and organs. It is involved in the development of the placenta, where it regulates trophoblast differentiation and function. In the lung, ELF5 is required for proper branching morphogenesis and differentiation of respiratory epithelial cells. It also plays a role in the development of the kidney, liver, and skin.

Regulation

The expression of ELF5 is tightly regulated during development and in adult tissues. Several factors, including hormones and growth factors, influence its expression levels. For example, the hormone prolactin stimulates ELF5 expression in mammary epithelial cells during pregnancy, leading to the activation of milk production genes. Additionally, ELF5 expression is regulated by other transcription factors and signaling pathways, which fine-tune its activity in different cellular contexts.

Clinical Significance

Aberrant expression or function of ELF5 has been associated with various diseases and conditions. In breast cancer, ELF5 expression is often downregulated, leading to disrupted mammary gland development and impaired lactation. Loss of ELF5 function has also been linked to the development of aggressive and metastatic breast tumors. Furthermore, alterations in ELF5 expression have been observed in other cancers, such as ovarian and lung cancer, suggesting its potential as a diagnostic or therapeutic target.