Ring Finger Protein 43 (RNF43)

RNF43 is a HAP95 (AKAP8L) binding ubiquitin ligase that promotes cell growth and is upregulated in colon cancer.The deduced RNF43 protein contains a signal peptide and a RING finger motif. RNF43 expression in 15 of 18 additional colon cancer samples tested. Immunocytochemistry studies localized RNF43 to spotty granules in the cytoplasm, and further studies demonstrated that RNF43 is a secretory protein.

RNF43 contains a transmembrane domain 5-prime of the RING finger motif and 2 C-terminal nuclear localization signals. Indirect immunofluorescence and biochemical fractionation localized RNF43 protein to the endoplasmic reticulum, and showed that RNF43 colocalized with emerin (EMD) to the inner nuclear membrane.