Structural and molecular genetic studies of the MHC novel gene RP

The correlation of many HLA-associated autoimmune and genetic diseases with the polymorphic complement C4 genes may be attributed to the presence of disease susceptibility genes in close proximity to C4. Duplicated genes RP1 and RP2 were discovered 612 bp upstream of the human C4A and C4B genes, respectively. Elucidation of the complete RP cDNA sequence revealed that the putative RP protein consists of 364 amino acid residues and is basic and hydrophilic. The presence of a bipartite nuclear localization signal at residues 114-131 suggests that RP may be a nuclear protein.;MBP-RP fusion protein was produced and polyclonal antisera were generated by using the fusion protein for immunization. Western blot analysis showed that the endogenous RP protein is ;The complete genomic sequences for human RP1 and RP2 were determined. The 5;The DNA sequence for RP2 revealed a hybrid structure resulting from the fusion of RP with the tenascin-like Gene X and the truncation of the 5;Mouse RP cDNA sequence and genomic structures were determined. The mouse RP gene is also partially duplicated but the breakpoint of gene duplication resides upstream of Exon 5. A gene targeting construct has been made by inserting a neo gene to Exon 3 of the functional RP1 gene.;A gene rearrangement event of RP1 was discovered in a nasopharyngeal carcinoma (NPC) cell line. The DNA sequence close to the rearranged breakpoint was elucidated through the vector anchored-PCR technique. Precisely, the RP1 gene is spliced to a rearrangement partner at Exon 4. The consequence of this RP1 gene rearrangement remains to be determined.