tRNAs are essential modulators that recognize mRNA codons and bridge amino acids for mRNA translation.The tRNAs are heavily modified,which are essential for forming a complex secondary structure that facilitates codon...tRNAs are essential modulators that recognize mRNA codons and bridge amino acids for mRNA translation.The tRNAs are heavily modified,which are essential for forming a complex secondary structure that facilitates codon recognition and mRNA translation.In recent years,studies have identified the regulatory roles of tRNA modifications in mRNA translation networks.Misregulation of tRNA modifications is closely related to the progression of developmental diseases and cancers.In this review,we summarize the tRNA biogenesis process and then discuss the effects and mechanisms of tRNA modifications on tRNA processing and mRNA translation.Finally,we provide a comprehensive overview of the physiological and pathological functions of tRNA modifications,focusing on diseases including cancers.展开更多
tRNase Z （TRZ） is a ubiquitous endonuclease that removes the 3＇-trailer from precursor tRNAs during maturation. In yeast and animals, TRZ regulates the cell cycle via its （t）RNA processing activity; however, its ...tRNase Z （TRZ） is a ubiquitous endonuclease that removes the 3＇-trailer from precursor tRNAs during maturation. In yeast and animals, TRZ regulates the cell cycle via its （t）RNA processing activity; however, its physiological function in higher plants has not been well characterized. This study describes the identification of a rice （Oryza sativa） TRZ2 mutant; plants homozygous for the osatrz2 mutation were albinos with deficient chlorophyll content. A microscopic analysis of the mutant plants revealed that the transition of proplastids to chloroplasts was arrested at an early stage, and the number and size of the plastids in callus cells was substantially decreased. A genetic complementation test and an RNA interference analysis confirmed that disruption of OsaTRZ2 was responsible for the mutant phenotype. OsaTRZ2 is expressed in all rice tissues, but is preferentially expressed in leaves, sheathes, and calli. OsaTRZ2 was subcellularly localized in chloroplasts, and displayed tRNA 3＇-end processing activity in both in vitro and in vivo assays. In the osatrz2 mutants, transcription of plastid-encoded and nucleus- encoded RNA polymerases was severely reduced and moderately increased, respectively. These results suggest that the tRNA 3＇ processing activity of OsaTRZ2 contributes to chloroplast biogenesis.展开更多
基金funded by the National Natural Science Foundation of China(81922052,81974435,and 81772999)a Distinguished Young Scholars grant from the Natural Science Foundation of Guangdong(2019B151502011)the Guangzhou People’s Livelihood Science and Technology Project(201903010006)。
文摘tRNAs are essential modulators that recognize mRNA codons and bridge amino acids for mRNA translation.The tRNAs are heavily modified,which are essential for forming a complex secondary structure that facilitates codon recognition and mRNA translation.In recent years,studies have identified the regulatory roles of tRNA modifications in mRNA translation networks.Misregulation of tRNA modifications is closely related to the progression of developmental diseases and cancers.In this review,we summarize the tRNA biogenesis process and then discuss the effects and mechanisms of tRNA modifications on tRNA processing and mRNA translation.Finally,we provide a comprehensive overview of the physiological and pathological functions of tRNA modifications,focusing on diseases including cancers.
基金supported by the 863 Project (2012AA10A303)the Fundamental Research Funds for the Central Universities (2013PY020 and 2013PY062)
文摘tRNase Z （TRZ） is a ubiquitous endonuclease that removes the 3＇-trailer from precursor tRNAs during maturation. In yeast and animals, TRZ regulates the cell cycle via its （t）RNA processing activity; however, its physiological function in higher plants has not been well characterized. This study describes the identification of a rice （Oryza sativa） TRZ2 mutant; plants homozygous for the osatrz2 mutation were albinos with deficient chlorophyll content. A microscopic analysis of the mutant plants revealed that the transition of proplastids to chloroplasts was arrested at an early stage, and the number and size of the plastids in callus cells was substantially decreased. A genetic complementation test and an RNA interference analysis confirmed that disruption of OsaTRZ2 was responsible for the mutant phenotype. OsaTRZ2 is expressed in all rice tissues, but is preferentially expressed in leaves, sheathes, and calli. OsaTRZ2 was subcellularly localized in chloroplasts, and displayed tRNA 3＇-end processing activity in both in vitro and in vivo assays. In the osatrz2 mutants, transcription of plastid-encoded and nucleus- encoded RNA polymerases was severely reduced and moderately increased, respectively. These results suggest that the tRNA 3＇ processing activity of OsaTRZ2 contributes to chloroplast biogenesis.
