Genetic control of tRNA methylation in inbred mice

Abstract

The tRNA methyltransferases from widely divergent species differ in their activity levels and base specificities (Borek and Kerr, 1972; Kerr and Borek, 1972; Srinivasan and Borek, 1964). However, very little is known about intra-species differences in activities of these enzymes except for those found in bacterial mutants which lack certain base-specific tRNA methylases (Bjork and Isaksson, 1970; Yang et al., 1973) and in rat liver tRNA methylases which exhibit sex specific activity differences ((Wainfan et al., 1980). In order to learn whether there are geneticallydetermined intra-species differences in mammalian tRNA methyltransferases, we are investigating various characteristics of these enzymes in inbred strains of mice. Since the tRNA methyltransferases are known to have altered activities in tumors and during chemically induced carcinogenesis (Borek and Kerr, 1972; Craddock, 1970; Hancock and Forrester, 1973; Kerr and Borek, 1972; Wainfan et al., 1975, 1977, 1978, 1979) it seemed of interest to compare the enzymes from inbred mice with either high (AKR/J) or low (C57BL.6J) incidence of spontaneous leukemia (Altman and Katz, 1979).