TRF4

Trf4, also known as Tetherin, is a protein that plays a crucial role in the regulation of the immune system. It is a member of the tetratricopeptide repeat (TPR) family of proteins, which are characterized by their repeated TPR motifs. Trf4 is primarily expressed in immune cells, including T cells, B cells, and dendritic cells.

The primary function of Trf4 is to regulate the activity of the transcription factor NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells). NF-κB is a key regulator of the immune response, and its activity is tightly controlled by Trf4. Trf4 achieves this by binding to the NF-κB p65 subunit and inhibiting its transcriptional activity. This inhibition is essential for maintaining immune homeostasis and preventing excessive inflammation.

Trf4 also plays a role in the regulation of apoptosis, or programmed cell death, in immune cells. It has been shown to induce apoptosis in activated T cells, which is important for the resolution of immune responses and the prevention of autoimmunity.

In addition to its role in the immune system, Trf4 has been implicated in other biological processes, including cell cycle regulation and DNA repair. However, the exact mechanisms by which Trf4 regulates these processes are not yet fully understood.

Trf4 is encoded by the TRF4 gene, which is located on chromosome 19 in humans. Mutations in the TRF4 gene have been associated with various immune-related disorders, including autoimmune diseases and lymphoproliferative disorders. However, the specific role of Trf4 in these disorders is still a topic of ongoing research.