The 3′-untranslated region directs ribosomal protein-encoding mRNAs to specific cytoplasmic regions

Abstract

mRNA localization is a conserved post-transcriptional process crucial for a variety of systems. We have analyzed the subcellular distribution of mRNAs encoding human cytosolic and mitochondrial ribosomal proteins. Biochemical fractionation experiments showed that the transcripts for cytosolic ribosomal proteins associate preferentially with the cytoskeleton via actin microfilaments. Transfection in HeLa cells of a GFP reporter construct containing the cytosolic ribosomal protein L4 3'-UTR showed that the 3'-UTR is necessary for the association of the transcript to the cytoskeleton. Using confocal analysis we demonstrate that the chimeric transcript is specifically associated with the perinuclear cytoskeleton. We also show that mRNA for mitochondrial ribosomal protein S12 is asymmetrically distributed in the cytoplasm. In fact, this transcript was localized mainly in the proximity of mitochondria, and the localization was 3'-UTR-dependent. In summary, ribosomal protein mRNAs constitute a new class of localized transcripts that share a common localization mechanism.

An Upstream Open Reading Frame and the Context of the Two AUG Codons Affect the Abundance of Mitochondrial and Nuclear RNase H1

“…RNase H1 destined for mitochondria represents only a small fraction of that present in the nucleus. Given the overall preference to produce the nuclear isoform of RNase H1, it might be beneficial for translation of Rnaseh1 mRNA to occur near mitochondria leading to cotranslational import, another mechanism for directing nuclearly encoded mitochondrial proteins (1,29). Cotranslational import makes little sense if the mRNA is translated to make the nuclear isoform.…”

Regulation of axonal trafficking of cytochrome c oxidase IV mRNA

“…Scale bar, 100 μm (C) SCG cultures (6 DIV) were transfected with the dGFP constructs as described in (A). Total RNA was prepared in the presence of 3 mM MgCl 2 from an enriched mitochondrial fraction in distal axons following the protocols described in (Russo et al, 2006). Quantitation of dGFP mRNA levels from total mitochondrial RNA was determined by qRT-PCR 24 h after DNA transfection.…”

Repression of Mitochondrial Translation, Respiration and a Metabolic Cycle-Regulated Gene, SLF1, by the Yeast Pumilio-Family Protein Puf3p

“…In yeast, many nucleus-derived transcripts encoding mitochondrial proteins are localized to mitochondrial-bound ribosomes via information residing in their 3′-UTR [19]. The mRNA localization phenomenon is apparently conserved, as human MrpS12 mRNA associates with mitochondria in a 3′-UTR dependent fashion [20]. In addition to its role in promoting mRNA decay, Puf3p also is important for mitochondrial transcript localization.…”