UB4A

UB4A (also known as UB4a-GRR) is a small, highly non-proteinogenic cyclic peptide developed by UB Therapeutics in collaboration with the Technion - Israel Institute of Technology. It is designed to target multiple myeloma by selectively binding to Lys48-linked ubiquitin chains (specifically K48-linked tetra-ubiquitin). By binding to these chains, UB4A blocks the action of deubiquitinases (DUBs) and impairs the recognition and subsequent degradation of ubiquitinated proteins by the proteasome. This novel mechanism of action disrupts the ubiquitin-proteasome system (UPS) and induces apoptosis in cancer cells, demonstrating potent anti-tumor activity in preclinical models, including those resistant to the standard proteasome inhibitor bortezomib.

Other names

Ub4aUb-4aUb 4a