LRRC58 (leucine-rich repeat containing 58) functions as a substrate adaptor for an E3 ubiquitin ligase complex that regulates cysteine catabolism through proteasomal degradation of CDO1, the rate-limiting enzyme in cysteine-to-taurine conversion 1. The protein exhibits ubiquitin-like ligase-substrate adaptor activity and participates in Cul5-RING ubiquitin ligase complex assembly 1. LRRC58-mediated CDO1 degradation is regulated by cysteine abundance, such that LRRC58 depletion stabilizes CDO1 and increases cysteine flux toward taurine production 1. This metabolic regulation has clinically relevant consequences: elevated taurine production promotes cholesterol excretion from hepatocytes, and LRRC58 depletion in mice lowers hepatic cholesterol levels 1. Beyond metabolic functions, LRRC58 has been identified as a potential epigenetic biomarker for prostate cancer, with aberrant DNA methylation detected in tumor samples 23. The gene underwent proteomic profiling in chemoproteomics screens examining drug responses 4. These findings establish LRRC58 as a key regulator of cysteine-taurine-cholesterol homeostasis with potential diagnostic applications in cancer detection.