JZY3032 and Domain‑ALTeration Chimeras: A New Class of Proximity‑Based Therapeutics

Chemical‑induced proximity (CIP) strategies have expanded the therapeutic toolbox by modulating protein–protein interactions, but classical approaches such as PROTACs and molecular glues often force unnatural pairings or stabilize existing interfaces, leading to variable or unpredictable effects. Domain‑ALTeration Chimeras (DALTACs) take a different path: instead of degrading targets or reinforcing native contacts, they selectively miswire endogenous protein complexes by enforcing non‑productive domain–domain interactions between physiologic partners.
In short, a DALTAC is a small molecule that links together two parts of a natural protein complex in a way that looks like the complex is still formed, but it cannot work properly. Instead of destroying the proteins or making their interaction stronger, it jams their normal architecture so they cannot communicate or turn on genes. This selectively blocks disease‑driving activities, such as oncogenic transcription, while leaving the proteins themselves intact.

JZY3032, is the first‑in‑class molecule targeting the androgen receptor (AR)–p300 transcriptional complex, a key regulatory node in prostate cancer. The AR–p300 interaction is central to androgen‑driven gene expression, where p300’s bromodomain recognizes acetylated histones and its histone acetyltransferase (HAT) activity helps drive enhancer activation and transcriptional output. In this setting, the AR’s N‑terminal domain (NTD) engages p300 to form a productive complex that supports oncogenic transcription. JZY3032 is designed to intercept this interaction without destroying either protein. The molecule consists of an AR ligand‑binding‑domain (LBD) inhibitor linked to a selective p300 bromodomain inhibitor through a tunable connector, such that both pharmacophores bind their respective partners simultaneously. The linker geometry is optimized so that when AR and p300 are both engaged, the relative orientation of their domains prevents the AR NTD from productively contacting p300, effectively decoupling the transcription‑activating functions of the complex.

This mode of action is distinct from PROTACs, which rely on recruiting an E3 ubiquitin ligase to polyubiquitinate and degrade the target protein, and from molecular glues, which typically stabilize or create new interfaces that favor particular conformations. JZY3032 does not trigger degradation; it does not lock the native AR–p300 interface in a hyper‑active state; instead, it reconfigures the complex topology so that the interacting domains are brought together but in a way that blocks productive communication. The result is suppression of enhancer activation and downstream transcriptional programs driven by the AR–p300 complex, without altering the steady‑state levels of AR or p300. This “topology‑only” intervention is conceptually closer to a silent, non‑productive ternary complex that occupies the interface but cannot transmit the signals or recruit the cofactors required for full transcriptional output.

Functionally, JZY3032 potently inhibits the growth of prostate cancer models that are co‑dependent on AR and p300, while sparing AR‑negative lineages. This lineage‑selective effect is consistent with the idea that the compound disrupts a specific, physiologic complex rather than acting as a general cytotoxic agent. In AR‑ and p300‑co‑dependent cells, the AR–p300 axis is required for maintaining the transcriptional program that supports proliferation and survival; by miswiring this complex, JZY3032 effectively silences part of that program without necessarily eliminating either AR or p300. In contrast, AR‑negative cells do not rely on this interaction for their growth, and thus they are largely unaffected by the compound. This pattern of activity mirrors the therapeutic rationale behind other targeted agents in oncology, where drugs are designed to exploit specific dependencies of malignant cells while sparing normal tissues that do not share those dependencies.

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