Comprehensive Analysis of Transcript Start Sites in Ly49 Genes Reveals an Unexpected Relationship with Gene Function and a Lack Of Upstream Promoters

摘要: Comprehensive analysis of the transcription start sites Ly49 genes C57BL/6 mice using oligo-capping 5′-RACE technique revealed that encoding “missing self” inhibitory receptors, Ly49A, C, G, and I, were transcribed from multiple broad regions in exon 1, intron1/exon2 region, upstream -1b. Ly49E was also this manner, uniquely showed a transcriptional shift exon1 to 2 when NK cells activated vitro with IL2. Remarkably, large proportion transcripts then initiated downstream translational codon. By contrast, Ly49B Q myeloid cells, activating Ly49D H receptors Ly49F T predominantly conserved site pyrimidine-rich region 1. An ∼200 bp fragment displayed tissue-specific promoter activity dendritic cell lines, but corresponding fragments all other lacked detectable activity. In particular, none any significant newly developed adult line expressed receptors. Similarly, no could be found intron1/exon2. Collectively, these findings reveal previously unrecognized relationship between pattern expression/function indicate lymphoid is achieved manner does not require classical promoters.