A candidate prostate cancer susceptibility gene encodes tRNA 3' processing endoribonuclease

Abstract

tRNA 3' processing endoribonuclease (3' tRNase) is an enzyme responsible for the removal of a 3' trailer from precursor tRNA (pre-tRNA). We purified approximately 85 kDa 3' tRNase from pig liver and determined its partial sequences. BLAST search of them suggested that the enzyme was the product of a candidate human prostate cancer susceptibility gene, ELAC2, the biological function of which was totally unknown. We cloned a human ELAC2 cDNA and expressed the ELAC2 protein in Escherichia coli. The recombinant ELAC2 was able to cleave human pre-tRNA(Arg) efficiently. The 3' tRNase activity of the yeast ortholog YKR079C was also observed. The C-terminal half of human ELAC2 was able to remove a 3' trailer from pre-tRNA(Arg), while the N-terminal half failed to do so. In the human genome exists a gene, ELAC1, which seems to correspond to the C-terminal half of 3' tRNase from ELAC2. We showed that human ELAC1 also has 3'-tRNase activity. Furthermore, we examined eight ELAC2 variants that seem to be associated with the occurrence of prostate cancer for 3'-tRNase activity. Seven ELAC2 variants which contain one to three amino acid substitutions showed efficient 3'-tRNase activities, while one truncated variant, which lacked a C-terminal half region, had no activity.

RNase ZS1 processes UbL40 mRNAs and controls thermosensitive genic male sterility in rice

“…RNase Z proteins process the 3 0 ends of tRNAs 21,[23][24][25] . The CCA sequence in 3 0 terminal of the tRNA is critical for tRNA maturation and function.…”

“…RNase Z S1 activity was assayed as previously described 24 . Briefly, the labelled precursor tRNAs or Ub L40 RNA were incubated for 0.5, 1, 2 or 4 h at 37°C with 200 ng purified RNase Z S1 or enzymatic null RNase Z S1 H81L, in which a substitution of histidine by leucine in position 81 in the conserved enzymatic domain of RNase Z proteins causes the loss of enzymatic activity 47 .…”

ELAC2, a putative prostate cancer susceptibility gene product, potentiates TGF-β/Smad-induced growth arrest of prostate cells

“…As androgen can progress prostate cancer, it is possible that FAST-1 cooperated with ELAC2 via TGF-b/Smad pathway might be able to slow the progress of prostate cancer by androgen. Others have shown that the C-terminal part of ELAC2 (and thus distinct from Smad interaction region) has 3 0 -tRNase activity in yeast and mammals (Takaku et al, 2003;Chen et al, 2005b;Minagawa et al, 2005). It is of interest to examine whether the 3 0 -tRNase activity of ELAC2 is influenced by TGF-b/ Smad signaling.…”

“…Linkage analysis by Tavtigian et al (2001) showed that ELAC2 is a candidate prostate cancer susceptibility gene. Recently it has been reported that ELAC2 at its C-terminal region possesses tRNA 3 0 processing endoribonuclease (3 0 -tRNase) activity in yeast and mammals (Takaku et al, 2003;Chen et al, 2005b;Minagawa et al, 2005), and that ELAC2 interacts with g-tubulin to cause a delay in G2-M progression in Hela cells (Korver et al, 2003). However, the functional significance of ELAC2 is not well known.…”

Gene silencing by the tRNA maturase tRNase ZL under the direction of small-guide RNA

“…1 tRNase Z is one of the tRNA-maturing enzymes, which removes a 3 0 trailer from pre-tRNA. [2][3][4] Most tRNase Zs cleave pre-tRNAs immediately downstream of a discriminator nucleotide, onto which the CCA residues are added to produce mature tRNA, whereas tRNase Z from Thermotoga maritima exceptionally cleaves pre-tRNAs containing the CCA sequence precisely after the A residue to create the mature 3 0 -termini. 5 tRNase Zs can be divided into two groups: a short form (tRNase Z S ) that consists of 300-400 amino acids and a long form (tRNase Z L ) that contains 800-900 amino acids.…”