Sequencing of full-length 5’ end of canine Ataxia Telangiectasia Mutated cDNA and characterization of the promoter region

The predicted canine ATM locus is annotated in a canine chromosome 5 region (Dog Genome assembly 2.0, Ensembl release 49) syntenic with human chromosome 11. Using 5’ RACE PCR, cloning and sequencing of mRNA purified from canine blood, the transcription start site of canine ATM was found on the reverse strand at CFA5: 27307661. To predict the putative promoter region, 700 bp genomic sequences upstream of the 5’ cap site were analyzed using Proscan software v1.7. A putative TATA-less bi-directional promoter region was found in the 371bp region upstream of the cap site. The core promoter harbours different conserved regulatory motifs: CREB, CCAAT boxes, SP1, GCF, XRE, ETS, Cre and c-Myb. When compared to the human and pig ATM/NPAT promoter, the canine cis-regulatory elements are highly conserved. Two exons, not annotated in the public database, were found in the 5’UTR. The cloned cDNA fragment extended from the transcription start site to exon 6. The putative translation start codon (XM_845871.1) corresponding to the N-terminus of human isoform 1, was found in exon 3. Two additional in-frame Met codons were located downstream in exons 5 and 6. The cloning of 5’ UTR could allow the investigation of the alternative splicing of canine ATM N-terminus.