HRD1 Proteins and Enzymes

HRD1 is a ubiquitin ligase whose expression is induced by the unfolded protein response (UPR) following endoplasmic reticulum stress. Expression of HRD1 protects cells from apoptosis by inducing degradation of abnormally processed proteins that accumulate in the endoplasmic reticulum. HRD1 is expressed in many tissues, strongly expressed in brain, pancreas, liver, kidney and skeletal muscle. It has been reported that Synoviolin/Hrd1 (expressed in rheumatoid synovium) is a novel causative factor for arthropathy by triggering synovial cell outgrowth through its anti-apoptotic effects. HRD1 contains one ring-type zinc finger.