Nucleocytoplasmic shuttling of the La motif-containing protein Sro9 might link its nuclear and cytoplasmic functions.
Diverse steps in gene expression are tightly coupled. Curiously, the La-motif-containing protein Sro9 has been shown to play a role in transcription and translation. Here, we show that Sro9 interacts with nuclear and cytoplasmic protein complexes involved in gene expression. In addition, Sro9 shuttles between nucleus and cytoplasm and is exported from the nucleus in an mRNA export-dependent manner. Importantly, Sro9 is recruited to transcribed genes. However, whole genome expression analysis shows that loss of Sro9 function does not greatly change the level of specific transcripts indicating that Sro9 does not markedly affect their synthesis and/or stability. Taken together, Sro9 might bind to the mRNP already during transcription and accompany the mature mRNP to the cytoplasm where it modulates translation of the mRNA.
Röther
Susanne
S
Department of Biochemistry, Ludwig-Maximilians-University Munich, Gene Center and Center for Integrated Protein Science Munich, 81377 Munich, Germany.
Burkert
Cornelia
C
Brünger
Katharina M
KM
Mayer
Andreas
A
Kieser
Anja
A
Strässer
Katja
K
D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D014158:Transcription, Genetic
D008840:Microfilament Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; C110018:SRO9 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins