TY - JOUR
T1 - Ubiquitin-mediated mRNP dynamics and surveillance prior to budding yeast mRNA export
AU - Iglesias, Nahid
AU - Tutucci, Evelina
AU - Gwizdek, Carole
AU - Vinciguerra, Patrizia
AU - Von Dach, Elodie
AU - Corbett, Anita H.
AU - Dargemont, Catherine
AU - Stutz, Françoise
PY - 2010/9/1
Y1 - 2010/9/1
N2 - The evolutionarily conserved mRNA export receptor Mex67/NXF1 associates with mRNAs through its adaptor, Yra1/REF, allowing mRNA ribonucleoprotein (mRNP) exit through nuclear pores. However, alternate adaptors should exist, since Yra1 is dispensable for mRNA export in Drosophila and Caenorhabditis elegans. Here we report that Mex67 interacts directly with Nab2, an essential shuttling mRNA-binding protein required for export. We further show that Yra1 enhances the interaction between Nab2 and Mex67, and becomes dispensable in cells overexpressing Nab2 or Mex67. These observations appoint Nab2 as a potential adaptor for Mex67, and define Yra1/REF as a cofactor stabilizing the adaptor-receptor interaction. Importantly, Yra1 ubiquitination by the E3 ligase Tom1 promotes its dissociation from mRNP before export. Finally, loss of perinuclear Mlp proteins suppresses the growth defects of Tom1 and Yra1 ubiquitination mutants, suggesting that Tom1-mediated dissociation of Yra1 from Nab2-bound mRNAs is part of a surveillance mechanism at the pore, ensuring export of mature mRNPs only.
AB - The evolutionarily conserved mRNA export receptor Mex67/NXF1 associates with mRNAs through its adaptor, Yra1/REF, allowing mRNA ribonucleoprotein (mRNP) exit through nuclear pores. However, alternate adaptors should exist, since Yra1 is dispensable for mRNA export in Drosophila and Caenorhabditis elegans. Here we report that Mex67 interacts directly with Nab2, an essential shuttling mRNA-binding protein required for export. We further show that Yra1 enhances the interaction between Nab2 and Mex67, and becomes dispensable in cells overexpressing Nab2 or Mex67. These observations appoint Nab2 as a potential adaptor for Mex67, and define Yra1/REF as a cofactor stabilizing the adaptor-receptor interaction. Importantly, Yra1 ubiquitination by the E3 ligase Tom1 promotes its dissociation from mRNP before export. Finally, loss of perinuclear Mlp proteins suppresses the growth defects of Tom1 and Yra1 ubiquitination mutants, suggesting that Tom1-mediated dissociation of Yra1 from Nab2-bound mRNAs is part of a surveillance mechanism at the pore, ensuring export of mature mRNPs only.
KW - Mex67/NXF1
KW - mRNA export
KW - Nab2
KW - Tom1
KW - Ubiquitination
KW - Yra1/REF
UR - http://www.scopus.com/inward/record.url?scp=77956277960&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77956277960&partnerID=8YFLogxK
U2 - 10.1101/gad.583310
DO - 10.1101/gad.583310
M3 - Article
C2 - 20810649
AN - SCOPUS:77956277960
SN - 0890-9369
VL - 24
SP - 1927
EP - 1938
JO - Genes and Development
JF - Genes and Development
IS - 17
ER -