Prediction, isolation, and sequencing of the promoter for human aminophospholipid translocase (APTL) II

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p‐Type ATPases drive translocation of phosphatidylserine (PS) and phosphatidyl‐ethanolamine (PE) from the outer to inner leaflet of the plasma membrane. This results in their inner‐leaflet sequestration, which is typical for healthy cells. The externalization of PS (and PE) during apoptosis labels apoptotic cells for phagocytosis by scavenger cells (e.g. microglia). Recently, coding sequences (partial cDNA and coding sequence based on a partial gene sequence) of the type II ATPase have been reported. Initial analysis of these sequences revealed an apparent lack of the 5′UTRs. In our attempts to elucidate the promoter, the transcription start site and the 5′ UTR of the APTL II gene, we compared these partial coding sequences to the EST's and genomic databases. This allowed us to elaborate exon/intron organization of ATPase II gene and revealed the possibility of existence of alternative splicing. We then analyzed the region in genomic DNA immediately upstream of the 5′end of the longest 5′EST clone, which revealed the presence of a CpG island. A TATA‐less promoter was predicted. We then amplified the part of the gene containing the promoter by PCR using genomic DNA as template. Cloning and sequencing revealed minor, though significant, differences between our sequence and its counterpart reported by Human Genome Project. Our studies will be followed up by 5′ RACE and analysis of the putative promoter region by its ability to drive an expression of a reporter gene. This will allow us to understand tissue specificity and the functional role of the APTLII enzyme.