Polyadenylate-binding protein, cytoplasmic and nuclear

Function

Binds the poly(A) tail of mRNA. Appears to be an important mediator of the multiple roles of the poly(A) tail in mRNA biogenesis, stability and translation. In the nucleus, interacts with the nuclear cleavage factor IA (CFIA), which is required for both mRNA cleavage and polyadenylation. Is also required for efficient mRNA export to the cytoplasm. Acts in concert with a poly(A)-specific nuclease (PAN) to affect poly(A) tail shortening, which may occur concomitantly with either nucleocytoplasmic mRNA transport or translational initiation. Regulates PAN activity via interaction with the stimulator PAN3 or the inhibitor PBP1. In the cytoplasm, affects both translation and mRNA decay. Stimulates translation by interaction with translation initiation factor eIF4G, a subunit of the cap-binding complex eIF4F, bringing the 5'- and 3'-ends of the mRNA in proximity. The formation of this circular mRNP structure appears to be critical for the synergistic effects of the cap and the poly(A) tail in facilitating translation initiation, recycling of ribosomes, and mRNA stability. Also regulates translation termination by recruiting eukaryotic release factor 3 (eRF3). Interaction with eRF3 is also required for regulation of normal mRNA decay through translation termination-coupled poly(A) shortening, probably mediated by PAN. Loss of PAB1 from the mRNP after deadenylation triggers mRNA degradation. Inhibits the major cytoplasmic mRNA deadenylase CCR4-NOT complex. Is also associated peripherally with COPI vesicles through its interaction with ARF1, and this is required for correct localization of the asymmetrically distributed ASH1 mRNA.

Classification

Family (Pfam)

PF00658 MLLE, PF00076 RRM_1

InterPro

Nucleotide-bd_a/b_plait_sf, PABP-dom, PABP_1234, PABP_HYD_C, PABP_RRM1, RBD_domain_sf, RRM2_I_PABPs, RRM_dom, RRM_euk-type

Functional cluster

Protein Serine/Threonine Kinases

Experimental structures · PDB · 2

• 1IFW NMR
• 6R5K EM 4.80A

A predicted model is available from AlphaFold.

Gene Ontology · 17

• GO:0005737 cytoplasm
• GO:0010494 cytoplasmic stress granule
• GO:0005829 cytosol
• GO:0005634 nucleus
• GO:1990904 ribonucleoprotein complex
• GO:0005840 ribosome
• GO:0140693 molecular condensate scaffold activity
• GO:0003730 mRNA 3'-UTR binding
• GO:0003729 mRNA binding
• GO:0008143 poly(A) binding
• GO:0008266 poly(U) RNA binding
• GO:1990841 promoter-specific chromatin binding
• GO:0008428 ribonuclease inhibitor activity
• GO:0031124 mRNA 3'-end processing
• GO:0051028 mRNA transport
• GO:0060211 regulation of nuclear-transcribed mRNA poly(A) tail shortening
• GO:0006446 regulation of translational initiation

Neighborhood · nearest proteins

Related proteins · sequence + function similarity

• Polyadenylate-binding protein, cytoplasmic and nuclear 0.99
• Polyadenylate-binding protein, cytoplasmic and nuclear 0.98
• Polyadenylate-binding protein, cytoplasmic and nuclear 0.98
• Polyadenylate-binding protein, cytoplasmic and nuclear 0.97
• Polyadenylate-binding protein, cytoplasmic and nuclear 0.97
• Polyadenylate-binding protein, cytoplasmic and nuclear 0.97
• Polyadenylate-binding protein, cytoplasmic and nuclear 0.96
• Polyadenylate-binding protein, cytoplasmic and nuclear 0.96
• Polyadenylate-binding protein, cytoplasmic and nuclear 0.95
• Polyadenylate-binding protein, cytoplasmic and nuclear 0.94
• Polyadenylate-binding protein 1 0.92
• Polyadenylate-binding protein 1-A 0.91

Co-cited proteins · studied together in the literature

• Eukaryotic peptide chain release factor GTP-binding subunit 5 shared papers
• Eukaryotic initiation factor 4F subunit p130 5 shared papers
• Eukaryotic initiation factor 4F subunit p150 5 shared papers
• Nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1 3 shared papers
• Polyadenylate-binding protein, cytoplasmic and nuclear 1 shared papers
• PAB1-binding protein 2 1 shared papers
• PAN2-PAN3 deadenylation complex catalytic subunit PAN2 2 shared papers
• mRNA 3'-end-processing protein RNA15 1 shared papers
• Protein SIS1 1 shared papers
• Coatomer subunit beta 1 shared papers
• Exportin-1 1 shared papers
• PAB1-binding protein 1 1 shared papers

Literature · 42 cited papers

• The reference genome sequence of Saccharomyces cerevisiae: Then and now. G3 (Bethesda) · 2014
• Analysis of the proteome of Saccharomyces cerevisiae for methylarginine. J. Proteome Res. · 2013
• Sites of ubiquitin attachment in Saccharomyces cerevisiae. Proteomics · 2012
• Global analysis of Cdk1 substrate phosphorylation sites provides insights into evolution. Science · 2009
• A multidimensional chromatography technology for in-depth phosphoproteome analysis. Mol. Cell. Proteomics · 2008
• Approaching a complete repository of sequence-verified protein-encoding clones for Saccharomyces cerevisiae. Genome Res. · 2007
• Tpa1p is part of an mRNP complex that influences translation termination, mRNA deadenylation, and mRNA turnover in Saccharomyces cerevisiae. Mol. Cell. Biol. · 2006
• Yeast poly(A)-binding protein Pab1 shuttles between the nucleus and the cytoplasm and functions in mRNA export. RNA · 2005
• Yeast poly(A)-binding protein, Pab1, and PAN, a poly(A) nuclease complex recruited by Pab1, connect mRNA biogenesis to export. Genes Dev. · 2005
• A faux 3'-UTR promotes aberrant termination and triggers nonsense-mediated mRNA decay. Nature · 2004
• Arf1p provides an unexpected link between COPI vesicles and mRNA in Saccharomyces cerevisiae. Mol. Biol. Cell · 2004
• The GTP-binding release factor eRF3 as a key mediator coupling translation termination to mRNA decay. J. Biol. Chem. · 2004
• … and 30 more in the literature graph