RNF139

RNF139 is a gene that encodes a protein also called RNF139, which functions as an E3 ubiquitin ligase. It is also known as ARA54, RING finger protein 139, and ZNF312.

RNF139 is implicated in various cellular processes, including endoplasmic reticulum (ER) stress response, lipid droplet formation, and the regulation of cellular lipid metabolism. It is an integral membrane protein primarily located in the endoplasmic reticulum. Its E3 ubiquitin ligase activity allows it to target specific proteins for ubiquitination, a process that often marks proteins for degradation by the proteasome or alters their function.

Research suggests that RNF139 plays a role in maintaining cellular homeostasis under stress conditions, specifically ER stress caused by the accumulation of unfolded or misfolded proteins. It has been shown to be involved in the turnover of specific ER proteins, contributing to the resolution of ER stress.

Furthermore, RNF139 has been linked to lipid droplet biogenesis and growth. Its involvement in lipid metabolism suggests a potential role in metabolic disorders, such as obesity and non-alcoholic fatty liver disease (NAFLD). Specifically, it has been shown to regulate the size and number of lipid droplets within cells.

The precise mechanisms and substrate specificity of RNF139 are still under investigation. Ongoing research aims to elucidate its precise role in these complex cellular processes and its potential as a therapeutic target for metabolic diseases and other conditions.