Molecular cloning of testis-abundant finger protein/ring finger protein 23(RNF23), a novel RING-B box-coiled coil-B30.2 protein on the class I region of the human MHC

We have identified a genomic DNA fragment, using the PCR method with degene rate oligonucleotide primers which contain the conserved sequence of the RI NG finger domain. Using the DNA fragment as a probe, a novel cDNA was clone d from human and mouse testis, The cDNA had a domain structure of the typic al RING-B box-coiled coil (RBCC)-B30.2 domain and therefore was named testi s-abundant finger protein (tfp). Indeed, the transcript was highly expresse d in the testis, although it was also found ubiquitously in various organs by Northern blot analysis. The tfp gene was mapped at the class I region of the human MHC (major histocompatibility complex), within which some known RBCC-B30.2 proteins such as RFP, RFB30/HERF1, AFP, and HZF had been localiz ed. These findings demonstrate that several RBCC-B30.2 proteins including t fp, which are non-HLA proteins, are clustered within the class I region of the human MHC. (C) 2000 Academic Press.