The measurement of the production of tRNAMet1 in the Friend erythroleukemia cell.
We have used the gene for tRNAMet1 as a hybridization probe to measure the production of tRNAMet1 in the Friend erythroleukemia cell. In this cell, the relative concentration of tRNAMet1 (i.e., the percentage of total steady-state tRNA representing tRNAMet1) is 1.60 +/- 0.18. To study the relative synthesis of tRNAMet1, cells were labeled in vivo with [3H]uridine for periods ranging from 4 to 24 h, and the tRNA was isolated. The fraction of newly-synthesized tRNA representing tRNAMet1 (1.72% +/- 0.11) does not change when different in vivo labeling times are used. This value is similar to the relative concentration of tRNAMet1 in the older steady-state tRNA (1.61% +/- 0.18). The similar relative synthesis values using different labeling times, plus evidence presented that the total tRNA population decays homogeneously (t 1/2 = 110 h) indicate that tRNAMet1 has a cytoplasmic stability similar to the general tRNA population, and that its concentration relative to the tRNA population is established within the nucleus or soon after exiting the nucleus. Measurements of the synthesis of tRNAMet1 in isolated nuclei, relative to the synthesis of total RNA polymerase III transcripts, showed that this relative synthesis (0.291% +/- 0.017) is only 17% of the relative concentration of tRNAMet1 in the cytoplasm, which may reflect the presence of sequences other than tRNA in total nuclear polymerase III transcripts.
Kleiman
L
L
Schmedt
E
E
Essagian
C
C
D000818:Animals; D002460:Cell Line; D007700:Kinetics; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism; D007942:Leukemia, Experimental / Q000378:metabolism*; D051379:Mice; D009693:Nucleic Acid Hybridization; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics* / Q000302:isolation & purification; D014158:Transcription, Genetic
D012346:RNA, Transfer, Amino Acyl; C026464:tRNA(m)(Met), methionine-