Genomic organization and transcriptional analysis of the human genes coding for caveolin-1 and caveolin-2

Caveolin-1 and caveolin-2 are related proteins involved in the biogenesis o f caveolae. The corresponding genes in humans (CAV and CAV2, respectively), have been mapped to a common locus in chromosome 7q31.1, and are possible candidates for the tumor suppressor gene postulated in this region. Here, w e show that CAV and CAV2 are independent transcriptional units lying in the same orientation, with CAV2 centromeric and about 17 kb upstream to CAV. T he two genes have similar tissue expression patterns. Alternative terminati on/polyadenylation generates two CAV2 mRNAs. Multiple transcriptional start sites spanning 35 bp upstream from the CAV2 ATG are detected by 5' RACE, c onsistent with a TATA-less promoter predicted by sequence analysis. The CAV 2 promoter region contains two SRE-like boxes resembling those described in the CAV promoter and proposed to link transcription to intracellular chole sterol levels. However, exogenous sterols had only minor effects on CAV and CAV2 RNA levels in HeLa cells, suggesting that SREBPs are not sufficient t o regulate caveolin transcription. (C) 2000 Elsevier Science B.V. All right s reserved.