Open AccessPoly(A)-Binding Protein-Interacting Protein 1 Binds to Eukaryotic Translation Initiation Factor 3 To Stimulate Translation
Author(s) -
Yvan Martineau,
Mélanie C. Derry,
Xiaoshan Wang,
Akiko Yanagiya,
Juan José Berlanga,
AnnBin Shyu,
Hiroaki Imataka,
Kalle Gehring,
Nahum Sonenberg
Publication year - 2008
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.00738-08
Subject(s) - eif4g , poly(a) binding protein , biology , eukaryotic translation initiation factor 4 gamma , eif4a1 , eukaryotic translation , eif4e , eukaryotic initiation factor , initiation factor , microbiology and biotechnology , ternary complex , translation (biology) , eif4ebp1 , messenger rna , biochemistry , gene , enzyme
Poly(A)-binding protein (PABP) stimulates translation initiation by binding simultaneously to the mRNA poly(A) tail and eukaryotic translation initiation factor 4G (eIF4G). PABP activity is regulated by PABP-interacting (Paip) proteins. Paip1 binds PABP and stimulates translation by an unknown mechanism. Here, we describe the interaction between Paip1 and eIF3, which is direct, RNA independent, and mediated via the eIF3g (p44) subunit. Stimulation of translation by Paip1 in vivo was decreased upon deletion of the N-terminal sequence containing the eIF3-binding domain and upon silencing of PABP or several eIF3 subunits. We also show the formation of ternary complexes composed of Paip1-PABP-eIF4G and Paip1-eIF3-eIF4G. Taken together, these data demonstrate that the eIF3-Paip1 interaction promotes translation. We propose that eIF3-Paip1 stabilizes the interaction between PABP and eIF4G, which brings about the circularization of the mRNA.