HUMAN GENE FOR THE RNA-POLYMERASE-II 7TH SUBUNIT (HSRPB7) - STRUCTURE, EXPRESSION AND CHROMOSOMAL LOCALIZATION

The human gene for the seventh largest subunit of RNA polymerase II co mplex, hsRPB7 was cloned, sequenced and mapped. This complex is an int egral part of the transcription-coupled DNA repair mechanism and has b een shown to be involved in several human genetic diseases and implica ted in many others. The hsRPB7 gene consists of 8 exons and spans appr oximately 5.1 kb. Southern blots of genomic and cloned DNA suggest tha t hsRPB7 is coded for by a single gene. Using human radiation hybrids and YACs, the gene was localized to 11q13.1, within 70 kb of marker D1 1S1765. The sequence of the 5' flanking region does not contain a TATA element, but does contain several Spl binding sites, an AP-1 site and a novel inverted polymorphic GATA tandem repeat. This novel GATA repe at can be used for linkage analysis. The hsRPB7 gene seems to be highl y conserved among eukaryotic species, showing general sequence conserv ation to yeast and Drosophila. Northern blot analysis reveals a high d egree of tissue-specific expression. For example, adult retina, brain and kidney exhibit a relatively high level of expression. A moderate l evel of expression is observed in heart, lung, testis, cornea, retinal pigmented epithelium/choroid and placenta with a lower level of expre ssion in the uterus, small intestine and skeletal muscle. A very low l evel of expression was observed in stomach and liver. Comparison betwe en four fetal and adult tissues also demonstrate a surprising level of developmental specificity. Expression in fetal retina is considerably lower than fetal brain but similar to adult retina. (C) 1997 Publishe d by Elsevier Science B.V.