RNF4

RNF4 (RING Finger Protein 4) is a protein that in humans is encoded by the RNF4 gene. This protein is a member of the RING finger family of proteins, which are characterized by the presence of a RING (Really Interesting New Gene) finger domain, a specialized type of zinc finger domain that mediates protein-protein interactions.

Function

RNF4 is involved in various cellular processes, including the regulation of transcription, DNA repair, and protein degradation. It functions as an E3 ubiquitin-protein ligase, which means it plays a crucial role in the process of ubiquitination, a post-translational modification where ubiquitin proteins are attached to a substrate protein. This modification can signal for the protein's degradation via the proteasome, alter its cellular location, affect its activity, or promote or prevent protein interactions.

Structure

The RNF4 protein contains a RING finger domain, which is essential for its function as an E3 ubiquitin ligase. This domain coordinates two zinc ions and is responsible for the interaction with E2 ubiquitin-conjugating enzymes. The protein also contains SUMO-interacting motifs (SIMs), which allow it to bind to SUMOylated proteins, targeting them for ubiquitination.

Clinical Significance

Mutations or dysregulation of RNF4 have been implicated in various diseases, including certain types of cancer. By targeting SUMOylated proteins for degradation, RNF4 helps maintain cellular homeostasis and prevents the accumulation of potentially harmful proteins.

Related Proteins

RNF4 is part of a larger family of RING finger proteins, which includes other members such as RNF2, RNF8, and RNF168. These proteins share a common RING finger domain but have distinct functions and regulatory mechanisms.

Research

Ongoing research is focused on understanding the precise mechanisms by which RNF4 and other RING finger proteins regulate cellular processes. This includes studies on their role in DNA damage response, cell cycle control, and signal transduction pathways.

See Also

• Ubiquitin
• Proteasome
• SUMOylation
• E3 ubiquitin ligase
• RING finger domain