GENETIC-ANALYSIS OF 2 RAT ACETYLTRANSFERASES

Single copies of two closely related acetyltransferase genes were dete cted in Sprague-Dawley derived rat DNA by Southern blot analysis using gene-specific hybridization probes for the 3' end of the acetyltransf erase coding regions, Sequence analysis of the two acetyltransferase g enes showed that both had intronless, 870 bp coding regions and coded for 290 amino acid protein sequences that were similar to 85% homologo us to one another. The calculated molecular weights were 33.4 and 33.9 kDa and the calculated isoelectric points 4.98 and 5.21 for AT1 and A T2, respectively, The inferred amino acid sequence of both the genes a nd cDNAs indicated that both rat acetyltransferases have cysteines at positions 44, 68 and 223 which have been conserved in all known verteb rate acetyltransferases. Transcripts for both AT1 and AT2 were detecte d in brain, colon, esophagus, heart, kidney, liver, lung, mammary glan d, dorsal prostate, ventral prostate, salivary gland, seminal vesicles , small intestine, spleen, stomach, testes, urinary bladder and uterus of Sprague-Dawley rats by both Northern blot and RT-PCR analysis, A t hird gene with >80% sequence homology to codons 118-158 of acetyltrans ferase was also detected.