Mammalian 2',3' cyclic nucleotide phosphodiesterase (CNP) can function as a tRNA splicing enzyme in vivo.
Yeast and plant tRNA splicing entails discrete healing and sealing steps catalyzed by a tRNA ligase that converts the 2',3' cyclic phosphate and 5'-OH termini of the broken tRNA exons to 3'-OH/2'-PO4 and 5'-PO4 ends, respectively, then joins the ends to yield a 2'-PO4, 3'-5' phosphodiester splice junction. The junction 2'-PO4 is removed by a tRNA phosphotransferase, Tpt1. Animal cells have two potential tRNA repair pathways: a yeast-like system plus a distinctive mechanism, also present in archaea, in which the 2',3' cyclic phosphate and 5'-OH termini are ligated directly. Here we report that a mammalian 2',3' cyclic nucleotide phosphodiesterase (CNP) can perform the essential 3' end-healing steps of tRNA splicing in yeast and thereby complement growth of strains bearing lethal or temperature-sensitive mutations in the tRNA ligase 3' end-healing domain. Although this is the first evidence of an RNA processing function in vivo for the mammalian CNP protein, it seems unlikely that the yeast-like pathway is responsible for animal tRNA splicing, insofar as neither CNP nor Tpt1 is essential in mice.
Schwer
Beate
B
Aronova
Anna
A
Ramirez
Alejandro
A
Braun
Peter
P
Shuman
Stewart
S
D063309:2',3'-Cyclic Nucleotide 3'-Phosphodiesterase; D000818:Animals; D005816:Genetic Complementation Test; D009154:Mutation; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011130:RNA Ligase (ATP) / Q000737:chemistry / Q000235:genetics; D012326:RNA Splicing; D012343:RNA, Transfer / Q000378:metabolism*; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics; D000090324:Tumor Protein, Translationally-Controlled 1
D029701:Saccharomyces cerevisiae Proteins; C000715648:Tpt1 protein, mouse; C000715649:Tpt1 protein, rat; D000090324:Tumor Protein, Translationally-Controlled 1; D012343:RNA, Transfer; D010727:Phosphoric Diester Hydrolases; D063309:2',3'-Cyclic Nucleotide 3'-Phosphodiesterase; C571338:Cnp protein, mouse; C571339:Cnp protein, rat; D011130:RNA Ligase (ATP); C507673:Trl1 protein, S cerevisiae