Ring Finger Protein 12 (RNF12)

E3 ubiquitin-protein ligase RLIM has been shown to be a ubiquitin protein ligase that targets LIM domain binding 1 (LDB1/CLIM), and causes proteasome-dependent degradation of LDB1. This protein and LDB1 are co-repressors of LHX1/LIM-1, a homeodomain transcription factor. Alternatively spliced transcript variants encoding the same protein have been reported. Analysis of mutated or truncated forms of RLIM demonstrated that the interaction domain is restricted to a basic evolutionarily conserved and centrally located region of approximately 100 amino acids. A combined EMSA and in vitro ubiquitination analysis, as well as chromatin immunoprecipitation analysis, indicated that RLIM, dependent on the presence of the RING finger, is able to ubiquitinate CLIM cofactors associated with DNA-bound LHX3.