Identification of a tRNA-specific Nuclear Export Receptor

Mol Cell. 1998 Feb;1(3):359-69. doi: 10.1016/s1097-2765(00)80036-2.

Abstract

In eukaryotes, tRNAs are synthesized in the nucleus and after several maturation steps exported to the cytoplasm. Here, we identify exportin-t as a specific mediator of tRNA export. It is a RanGTP-binding, importin beta-related factor with predominantly nuclear localization. It shuttles rapidly between nucleus and cytoplasm and interacts with nuclear pore complexes. Exportin-t binds tRNA directly and with high affinity. Its cellular concentration in Xenopus oocytes was found to be rate-limiting for export of all tRNAs tested, as judged by microinjection experiments. RanGTP regulates the substrate-exportin-t interaction such that tRNA can be preferentially bound in the nucleus and released in the cytoplasm.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cell Nucleus / chemistry*
  • Cell Nucleus / metabolism*
  • Cloning, Molecular
  • Cytoplasm / metabolism
  • GTP-Binding Proteins / metabolism
  • GTPase-Activating Proteins*
  • HeLa Cells
  • Humans
  • Molecular Sequence Data
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Nucleocytoplasmic Transport Proteins*
  • Oocytes / physiology
  • Protein Binding / physiology
  • RNA, Messenger / analysis
  • RNA, Transfer / metabolism*
  • RNA, Transfer, Amino Acid-Specific / metabolism
  • RNA, Transfer, Leu / metabolism
  • RNA, Transfer, Ser / metabolism
  • Xenopus
  • Xenopus Proteins
  • beta Karyopherins
  • ran GTP-Binding Protein

Substances

  • Carrier Proteins
  • GTPase-Activating Proteins
  • Nuclear Proteins
  • Nucleocytoplasmic Transport Proteins
  • RANGAP1 protein, human
  • RNA, Messenger
  • RNA, Transfer, Amino Acid-Specific
  • RNA, Transfer, Leu
  • RNA, Transfer, Ser
  • RanGAP1 protein, Xenopus
  • XPOT protein, human
  • Xenopus Proteins
  • beta Karyopherins
  • ran-binding protein 1
  • tRNA, selenocysteine-
  • RNA, Transfer
  • GTP-Binding Proteins
  • ran GTP-Binding Protein

Associated data

  • GENBANK/AF039022