A-kinase anchor protein 4 (AKAP-4) (AKAP-4)

A-kinase anchor protein 4 (AKAP-4) is a major structural and scaffolding protein primarily located in the fibrous sheath of the sperm flagellum, where it plays a critical role in regulating sperm motility and signal transduction by anchoring Protein Kinase A (PKA) [6, 8, 12]. It is a prominent member of the Cancer-Testis Antigen (CTA) family, characterized by restricted expression in the immune-privileged testis and aberrant upregulation in numerous malignancies, such as lung, breast, prostate, and colorectal cancers [1, 3, 5]. In the context of oncology, AKAP-4 functions as a pro-oncogenic factor that promotes cell proliferation, migration, and invasion while suppressing apoptosis and senescence [2, 10]. Its high immunogenicity and tumor-specific expression profile make it an attractive target for various immunotherapeutic strategies, including cancer vaccines, adoptive T-cell therapies, and CAR-T cells [3, 13]. Furthermore, the presence of AKAP-4 mRNA or circulating anti-AKAP-4 autoantibodies serves as a highly sensitive and specific biomarker for early-stage cancer detection and recurrence monitoring [11, 15]. While no drugs are currently approved, experimental approaches such as gene silencing and antigen-specific immunotherapy have shown significant potential in preclinical models [2, 13].

Other names

AKAP82CT99FSC1HIhAKAP82p82PRKA4Major sperm fibrous sheath protein

Immunotherapy (antigen-specific cytotoxic T-lymphocyte activation); Gene silencing (shRNA-mediated knockdown of protein expression)