Purification of nuclear poly(A)-binding protein Nab2 reveals association with the yeast transcriptome and a messenger ribonucleoprotein core structure.
Nascent mRNAs produced by transcription in the nucleus are subsequently processed and packaged into mRNA ribonucleoprotein particles (messenger ribonucleoproteins (mRNPs)) before export to the cytoplasm. Here, we have used the poly(A)-binding protein Nab2 to isolate mRNPs from yeast under conditions that preserve mRNA integrity. Upon Nab2-tandem affinity purification, several mRNA export factors were co-enriched (Yra1, Mex67, THO-TREX) that were present in mRNPs of different size and mRNA length. High-throughput sequencing of the co-precipitated RNAs indicated that Nab2 is associated with the bulk of yeast transcripts with no specificity for different mRNA classes. Electron microscopy revealed that many of the mRNPs have a characteristic elongated structure. Our data suggest that mRNPs, although associated with different mRNAs, have a unifying core structure.
Biochemie Zentrum der Universität Heidelberg (BZH), Im Neuenheimer Feld 307, D-69120 Heidelberg, Germany.
Julien
J
Batisse
Claire
C
Batisse
Aidan
A
Budd
Bettina
B
Böttcher
Ed
E
Hurt
D020869:Gene Expression Profiling; D009690:Nucleic Acid Conformation; D029543:Nucleocytoplasmic Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
C080773:NAB2 protein, S cerevisiae; D029543:Nucleocytoplasmic Transport Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins