RNF43

RNF43 is a protein that in humans is encoded by the RNF43 gene. RNF43 is an enzyme that functions as an E3 ubiquitin-protein ligase, a type of protein that tags other proteins for degradation. This protein plays a crucial role in cell growth and cell division, particularly in the gastrointestinal tract.

Function

RNF43 is a member of the RING finger protein family. It is an E3 ubiquitin-protein ligase that accepts ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfers the ubiquitin to targeted substrates. This protein plays a role in the Wnt signaling pathway, a pathway that is involved in cell growth and differentiation. It negatively regulates the pathway by targeting the Frizzled receptor for ubiquitination and degradation.

Clinical significance

Mutations in the RNF43 gene have been associated with various types of cancer, including colorectal cancer, pancreatic cancer, and ovarian cancer. These mutations often result in a loss of function of the RNF43 protein, leading to an overactivation of the Wnt signaling pathway and uncontrolled cell growth.

File:RNF43 protein structure.jpg

The structure of the RNF43 protein. Image from Wikimedia Commons.

See also

• RING finger domain
• Ubiquitin-protein ligase
• Wnt signaling pathway
• Frizzled