CHARACTERIZATION OF THE MURINE PIG-A PROMOTER REGION HIGH CONSTITUTIVE PIG-A GENE-EXPRESSION IN BRAIN

PIG-A is an X-linked gene that encodes a synthetic element required to initiate glycoinositol phospholipid (GPI) anchor assembly. In this st udy we characterized genomic sequence flanking the previously identifi ed 5' end of the murine PIG-A gene and analyzed constitutive levels of PIG-A gene expression in vivo in different tissues. We found that the 5'-flanking sequence contains 1) alternative transcriptional start si tes at -154 and -34/-33 relative to previously known exon 1 sequence, 2) all MRE and multiple GRE, Ap-2 and Sp-1 consensuses, and 3) a 100-b p-long GC-rich segment bounded by NF-IL6 sites. Our survey of PIG-A mR NA levels ill Ino unexpectedly revealed that PIG-A expression levels a re 2-4 fold higher in the brain than in other tissues (C) 1995 Academi c Press, Inc.