A Mouse Single-Copy Gene,Gtf2i,the Homolog of HumanGTF2I,That Is Duplicated in the Williams–Beuren Syndrome Deletion Region

Abstract

We have cloned and characterizedGtf2i,the mouse homolog of humanGTF2I(general transcription factor II-I), which encodes BAP-135, a target for Bruton's tyrosine kinase.GTF2Irepresents the telomeric and functional copy of a duplicated gene flanking the 2-Mb Williams–Beuren syndrome (WBS) common deletion at 7q11.23.GTF2Iis deleted in WBS, while a truncated centromeric pseudogene (GTF2IP1) is not deleted. In mouse, there appears to be only a single locus,Gtf2i,which we mapped to mouse chromosome 5 in a region of conserved mouse–human synteny.Gtf2iis 87.7% identical toGTF2Iat the nucleotide and 97% at the amino acid level and generates several alternatively spliced transcripts. The gene is widely expressed in adult tissues and equally in all areas of the brain.Gtf2itranscript is detectable in ES cells by RT-PCR and on Northern blots of tissues from 7-dpc embryos. A ubiquitous expression pattern is seen by Northern and tissuein situhybridization studies of 14-dpc embryos.