E3 ubiquitin ligase TRIM2 identified as a novel suppressor of CYP11B2 and aldosterone production

Abstract

Aldosterone-producing adenoma (APA) is a leading cause of primary aldosteronism (PA), a condition marked by excessive aldosterone secretion. CYP11B2, the aldosterone synthase, plays a critical role in aldosterone biosynthesis and the development of APA. Despite its significance, encoding regulatory mechanisms governing CYP11B2, particularly its degradation, remain poorly understood. In this study, we sought to uncover novel regulators of CYP11B2 stability by conducting a siRNA screen targeting E3 ubiquitin ligases. Our results identified TRIM2 as a key negative regulator of CYP11B2, where its overexpression led to a significant reduction in CYP11B2 protein levels and a concomitant decrease in aldosterone production in adrenal tumor cells. Mechanistically, we demonstrated that TRIM2 interacts with CYP11B2 via its RBCC domain, promoting K29/48-linked polyubiquitination and destabilization of CYP11B2. Further results revealed that TRIM2 is downregulated in APA tissues, showing differential expression between the zona glomerulosa (ZG) and zona fasciculata (ZF) of normal adrenal tissue. These findings highlight TRIM2 as a novel modulator of aldosterone synthesis through CYP11B2 degradation, offering a potential therapeutic target for APA.