Coiled-coil domain-containing protein 85B (CCDC85B)

Coiled-coil domain-containing protein 85B (CCDC85B), also known as Delta-interacting protein A (DIPA), is a human protein encoded by the *CCDC85B* gene. It acts primarily as a **transcriptional repressor** and has been shown to interact with the hepatitis delta virus antigen, affecting HDV replication in vitro[1][3]. CCDC85B functions in cell growth regulation, potentially by inhibiting beta-catenin activity (CTNNB1) in a tumor suppressor p53-dependent manner, and is involved in cell-cell adhesion and epithelial development through interactions with beta-catenin family proteins[4][5]. It may also play a role in adipocyte differentiation and negatively regulate mitotic expansion[4]. Disease associations include roles in hepatitis (specifically in the viral life cycle of HDV), non-small cell lung cancer (where it has been reported to promote proliferation and invasion through activation of the AKT/GSK3β/β-catenin oncogenic pathway), and hereditary spastic paraplegia[2][3]. There are no known drugs that directly target CCDC85B, nor is it currently recognized as a therapeutic target or established biomarker in clinical settings.

Other names

Delta-interacting protein ADIPAHepatitis delta antigen-interacting protein ACCDC85B