The nucleotide excision repair (NER) disorder xeroderma pigmentosum (XP) is characterized by sun (UV) sensitivity, predisposition to skin cancer, and extensive genetic heterogeneity. Recently, we reported the cloning and analysis of three human NER genes, XPC, HHR23A, and HHR23B. The previously cloned XPC gene is involved in the common XP complementation group C, which is defective in excision repair of non-transcribed sequences in the genome. The XPC protein was found to be complexed with the product of HHR23B, one of the two human homologs of the Saccharomyces cerevisiae NER gene RAD23. Here we present the chromosomal localization by in situ hybridization using haptenized probes of all three genes. The HHR23A gene was assigned to chromosome 19p13.2. Interestingly, the HHR23B and XPC genes, the product of which forms a tight complex, were found to colocalize on band 3p25.1. Pulsed-field gel electrophoresis revealed that the HHR23B and XPC genes possibly share a MluI restriction fragment of about 625 kb. Potential involvement of the HHR23 genes in human genetic disorders is discussed.

Additional Metadata
Keywords *Chromosomes, Human, Pair 19, *Chromosomes, Human, Pair 3, Animals, Chromosome Mapping, Comparative Study, DNA Repair/*genetics, Deoxyribonucleases, Type II Site-Specific, EC 3.1.21.4 (BglII endonuclease), EC 3.1.21.4 (Deoxyribonucleases, Type II Site-Specific), Genes, Fungal, Genetic Complementation Test, Hominidae/*genetics, Human, In Situ Hybridization, Lymphocytes/cytology/metabolism, Polymorphism, Restriction Fragment Length, Restriction Mapping, Saccharomyces cerevisiae/*genetics, Support, Non-U.S. Gov't, Xeroderma Pigmentosum/*genetics
Persistent URL dx.doi.org/10.1006/geno.1994.1554, hdl.handle.net/1765/3069
Journal Genomics
Citation
van der Spek, P.J, Smit, E.M.E, Beverloo, H.B, Sugasawa, K, Matsutani, C, Hanaoka, F, … Hagemeier, A. (1994). Chromosomal localization of three repair genes: the xeroderma pigmentosum group C gene and two human homologs of yeast RAD23. Genomics, 23(3), 651–658. doi:10.1006/geno.1994.1554