Translational Regulation Of Gene Expression Research Articles

Refinement of Leishmania donovani Genome Annotations in the Light of Ribosome-Protected mRNAs Fragments (Ribo-Seq Data).

Advances in next-generation sequencing methodologies have facilitated the assembly of an ever-increasing number of genomes. Gene annotations are typically conducted via specialized software, but the most accurate results require additional manual curation that incorporates insights derived from functional and bioinformatic analyses (e.g., transcriptomics, proteomics, and phylogenetics). In this study, we improved the annotation of the Leishmania donovani (strain HU3) genome using publicly available data from the deep sequencing of ribosome-protected mRNA fragments (Ribo-Seq). As a result of this analysis, we uncovered 70 previously non-annotated protein-coding genes and improved the annotation of around 600 genes. Additionally, we present evidence for small upstream open reading frames (uORFs) in a significant number of transcripts, indicating their potential role in the translational regulation of gene expression. The bioinformatics pipelines developed for these analyses can be used to improve the genome annotations of other organisms for which Ribo-Seq data are available. The improvements provided by these studies will bring us closer to the ultimate goal of a complete and accurately annotated L. donovani genome and will enhance future transcriptomics, proteomics, and genetics studies.

The IGF2BP3-COPS7B axis facilitates mRNA translation to drive colorectal cancer progression.

Many studies have provided valuable information about genomic and transcriptomic changes that occur in colorectal cancer (CRC). However, protein abundance cannot be reliably predicted by DNA alteration or mRNA expression, which can be partially attributed to post-transcriptional and/or translational regulation of gene expression. In this study, we identified increased translational efficiency (TE) as a hallmark of CRC by evaluating the transcriptomic and proteomic features of CRC patients, along with comparative transcriptomic and ribosome-protected mRNA analysis in colon epithelial cells and colon cancer cells. COPS7B was among the key genes that consistently showed both significant TE increase and protein elevation without transcriptional alteration in CRC. IGF2BP3 enhanced the TE of COPS7B mRNA to promote CRC growth and metastasis. COPS7B was found to be a component of the ribo-interactome that interacted with ribosomes to facilitate ribosome biogenesis and mRNA translation initiation. Collectively, this study revealed the proteomic features of CRC and highlighted elevated mRNA translation as a hallmark of CRC. The identification of the IGF2BP3-COPS7B axis underlying the increased protein synthesis rate in CRC provided a promising therapeutic target to treat this aggressive disease.

Local translation in perisynaptic and perivascular astrocytic processes - a means to ensure astrocyte molecular and functional polarity?

Together with the compartmentalization of mRNAs in distal regions of the cytoplasm, local translation constitutes a prominent and evolutionarily conserved mechanism mediating cellular polarization and the regulation of protein delivery in space and time. The translational regulation of gene expression enables a rapid response to stimuli or to a change in the environment, since the use of pre-existing mRNAs can bypass time-consuming nuclear control mechanisms. In the brain, the translation of distally localized mRNAs has been mainly studied in neurons, whose cytoplasmic protrusions may be more than 1000 times longer than the diameter of the cell body. Importantly, alterations in local translation in neurons have been implicated in several neurological diseases. Astrocytes, the most abundant glial cells in the brain, are voluminous, highly ramified cells that project long processes to neurons and brain vessels, and dynamically regulate distal synaptic and vascular functions. Recent research has demonstrated the presence of local translation at these astrocytic interfaces that might regulate the functional compartmentalization of astrocytes. In this Review, we summarize our current knowledge about the localization and local translation of mRNAs in the distal perisynaptic and perivascular processes of astrocytes, and discuss their possible contribution to the molecular and functional polarity of astrocytes.

RNA and DNA Binding Epitopes of the Cold Shock Protein TmCsp from the Hyperthermophile Thermotoga maritima

Prokaryotic cold shock proteins (CSPs) are considered to play an important role in the transcriptional and translational regulation of gene expression, possibly by acting as transcription anti-terminators and “RNA chaperones”. They bind with high affinity to single-stranded nucleic acids. Here we report the binding epitope of TmCsp from Thermotoga maritima for both single-stranded DNA and RNA, using heteronuclear 2D NMR spectroscopy. At “physiological” growth temperatures of TmCsp (≥ 343 K), all oligonucleotides studied have dissociation constants between 1.6 ((dT)7) and 25.2 ((dA)7) μM as determined by tryptophan fluorescence quenching. Reduction of the temperature to 303 K leads to a pronounced increase of affinity for thymidylate (dT)7 and uridylate (rU)7 heptamers with dissociation constants of 4.0 and 10.8 nM, respectively, whereas the weak binding of TmCsp to cytidylate, adenylate, and guanylate heptamers (dC)7, (dA)7, and (dT)7 is almost unaffected by temperature. The change of affinities of TmCsp for (dT)7 and (rU)7 by approximately 3 orders of magnitude shows that it represents a cold chock sensor that switches on the cold shock reaction of the cell. A temperature dependent conformational switch of the protein is required for this action. The binding epitope on TmCsp for the ssDNA and RNA heptamers is very similar and comprises β-strands 1 and 2, the loop β1–β2 as well as the loops connecting β3 with β4 and β4 with β5. Besides the loop regions, surprisingly, mainly the RNA-binding motif RNP1 is involved in ssDNA and RNA binding, while only two amino acids, H28 and W29, of the postulated RNA-binding motif RNP2 interact with the uridylate and thymidylate homonucleotides, although a high affinity in the nanomolar range is achieved. This is in contrast to the binding properties of other CSPs or cold shock domains, where RNP1 as well as RNP2 are involved in binding. TmCsp takes up a unique position since it is the only one which possesses a tryptophan residue instead of a usually highly conserved phenylalanine or tyrosine residue at the end of RNP2. NMR titrations suggest that neither (dT)7 nor (rU)7 represent the full binding motif and that non-optimal intercalation of W29 into these oligonucleotides blocks the access of the RNP2 site to the DNA or RNA. NMR-experiments with (dA)7 suggest an interaction of W29 with the adenine ring. Full binding seems to require at least one single purine base well-positioned within a thymine- or uracil-rich stretch of nucleic acids.

Abstract A56: Identification of circulating miRNA signatures in rectal cancer

Abstract Colorectal cancer is the third most common cancer and the second leading cause of cancer death in Europe. Therefore, the search for new biomarkers to enable facilitate early diagnosis, prognosis, and individualized treatment is particularly warranted. From a clinical point of view, malignancies in the colon and the rectum (RC) present two distinct entities that require different treatment strategies, so CRC might not be considered as a single enteropathogenic entity. MicroRNA (miRNAs) are small noncoding RNA molecules involved in the post-transcriptional and translational regulation of gene expression. The discovery that miRNAs may act either as oncogenes or tumor suppressors has initiated extensive research. It was recently discovered that extracellular miRNAs circulate in the bloodstream and that such circulating miRNAs are remarkably stable. This has raised the possibility that miRNAs might serve as novel markers for disease diagnosis and prognosis. In the present study, we aimed to identify circulating miRNAs enabling early diagnosis and prognosis of RC. MiRNA expression levels (from plasma and plasma exosomes) were characterized by next-generation sequencing (NGS) in 24 patients with RC collected at 2-time intervals. The first sampling was collected at the time of diagnosis and the second sampling was conducted around 1 year after the diagnosis. The expression levels of miR-122 and miR-142 were identified to be associated with overall survival in RC patients. Their functional characteristics were tested in vitro on rectal cancer cell lines HRA16 and SW1463. Increased levels of miRNAs were associated with decreased long-term survival of cells. Identified miRNAs are currently being verified on a larger population of RC patients. This has raised the question whether miRNA can serve as biomarkers for rectal cancer, but prior to its clinical applications, clinical trials are warranted. Acknowledgments: This work was supported by AZV 17-30920A, GA17-16857S, and GA UK 302119. Citation Format: Klara Cervena, Alena Opattova, Barbara Pardini, Alessio Naccarati, Pavel Vodicka, Veronika Vymetalkova. Identification of circulating miRNA signatures in rectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr A56.

Cytomorphic Electronics With Memristors for Modeling Fundamental Genetic Circuits.

Cytomorphic engineering attempts to study the cellular behavior of biological systems using electronics. As such, it can be considered analogous to the study of neurobiological concepts for neuromorphic engineering applications. To date, digital and analog translinear electronics have commonly been used in the design of cytomorphic circuits; Such circuits could greatly benefit from lowering the area of the digital memory via memristive circuits. In this article, we propose a novel approach that utilizes the Boltzmann-exponential stochastic transport of ionic species through insulators to naturally model the nonlinear and stochastic behavior of biochemical reactions. We first show that two-terminal memristive devices can capture the non-linear and stochastic behavior of biochemical reactions. Then, we present the design of several building blocks based on analog memristive circuits that inherently model the biophysical mechanisms of gene expression. The circuits model induction by small molecules, activation and repression by transcription factors, biological promoters, cooperative binding, and transcriptional and translational regulation of gene expression. Finally, we utilize the building blocks to form complex mixed-signal networks that can simulate the delay-induced oscillator and the p53-mdm2 interaction in the cancer signaling pathway. Our approach can provide a fast and simple emulative framework for studying genetic circuits and arbitrary large-scale biological networks in systems and synthetic biology. Some challenges may be that memristive devices with frequent learning and programming do not have the same longevity as traditional transistor-based electron-transport devices, and operate with significantly slower time constants, which can limit emulation speed.

Loss of the ribosomal RNA methyltransferase NSUN5 impairs global protein synthesis and normal growth.

Modifications of ribosomal RNA expand the nucleotide repertoire and thereby contribute to ribosome heterogeneity and translational regulation of gene expression. One particular m5C modification of 25S ribosomal RNA, which is introduced by Rcm1p, was previously shown to modulate stress responses and lifespan in yeast and other small organisms. Here, we report that NSUN5 is the functional orthologue of Rcm1p, introducing m5C3782 into human and m5C3438 into mouse 28S ribosomal RNA. Haploinsufficiency of the NSUN5 gene in fibroblasts from William Beuren syndrome patients causes partial loss of this modification. The N-terminal domain of NSUN5 is required for targeting to nucleoli, while two evolutionary highly conserved cysteines mediate catalysis. Phenotypic consequences of NSUN5 deficiency in mammalian cells include decreased proliferation and size, which can be attributed to a reduction in total protein synthesis by altered ribosomes. Strikingly, Nsun5 knockout in mice causes decreased body weight and lean mass without alterations in food intake, as well as a trend towards reduced protein synthesis in several tissues. Together, our findings emphasize the importance of single RNA modifications for ribosome function and normal cellular and organismal physiology.

Regulation of UGT2A1 by miR‐196a & miR‐196b and Its Implications for Lung Cancer Risk

Polycyclic aromatic hydrocarbons (PAH) are a class of highly lipophilic and mutagenic carcinogenic compounds found in tobacco smoke and incomplete combustion reactions. Once inside the cell, PAHs are oxidized by cytochrome P450s 1C1 and 1B1 to form reactive species that can form DNA adducts. PAHs are primarily detoxified by the UDP‐glucuronosyltransferase (UGT) family of enzymes, which comprise a major family of phase II metabolism responsible for the detoxification of a variety of endogenous and exogenous compounds including steroids, many drugs and chemotherapeutic agents, and carcinogens. UGT2A1 is an aero‐digestive tract‐expressing enzyme shown to be highly selective toward a broad range PAHs and is expressed in tobacco target tissues, including lung. microRNA (miRNA) are short, noncoding RNA sequences that play a role in translational regulation of gene expression by binding primarily to the 3′ untranslated regions (UTR) of mRNA. Significant (P<0.05 and P<0.001) decreases in luciferase activity were observed in cells over‐expressing heterologous vectors containing the 3′‐untranslated region (UTRs) of UGT2A1 with the miR‐196a and miR‐196b mimics, respectively. Pull‐down assays revealed miR‐196a and miR‐196b bound to the 3′ UTR of UGT2A1 at 3.4‐and 5.3‐fold higher levels, respectively, compared to the coding region control sequence. In the lung cancer cell lines, H1944 and H146, a significant trend is observed when cells were transfected with increasing levels of miR‐196a and miR‐196b (Ptrend=0.0065 and Ptrend=0.0114 for H1944, and Ptrend=0.0219 and Ptrend=0.0091 for H146, respectively). These data indicate that miR‐196a and miR‐196b may be important in regulating UGT2A1 expression in human tissues and may be potential biomarkers for cancer risk in smokers.Support or Funding InformationNational Institute of Environmental Health Sciences (NIEHS) of the National Institute of Health (NIH) to Dr. Philip Lazarus (Grant R01‐ES025460) and the Health Sciences and Services Authority of Spokane, WA (Grant WSU002292).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

RNA helicase, DDX27 regulates skeletal muscle growth and regeneration by modulation of translational processes.

Gene expression in a tissue-specific context depends on the combined efforts of epigenetic, transcriptional and post-transcriptional processes that lead to the production of specific proteins that are important determinants of cellular identity. Ribosomes are a central component of the protein biosynthesis machinery in cells; however, their regulatory roles in the translational control of gene expression in skeletal muscle remain to be defined. In a genetic screen to identify critical regulators of myogenesis, we identified a DEAD-Box RNA helicase, DDX27, that is required for skeletal muscle growth and regeneration. We demonstrate that DDX27 regulates ribosomal RNA (rRNA) maturation, and thereby the ribosome biogenesis and the translation of specific transcripts during myogenesis. These findings provide insight into the translational regulation of gene expression in myogenesis and suggest novel functions for ribosomes in regulating gene expression in skeletal muscles.

MicroRNA-664a-5p promotes neuronal differentiation of SH-SY5Y cells.

MicroRNAs (miRNAs) belong to a class of small noncoding RNAs that play important roles in the translational regulation of gene expression. A number of miRNAs are known to act as key regulators of diverse processes such as neuronal differentiation. In this study, we have attempted to identify novel miRNAs related to neuronal differentiation via microarray analysis in the human neuronal differentiation model neuroblastoma SH-SY5Y cells. We identified 15 up-regulated and eight down-regulated miRNAs in SH-SY5Y cells treated with all-trans retinoic acid to induce differentiation. We further showed that one of the up-regulated miRNAs, miR-664a-5p, promoted neuronal differentiation of SH-SY5Y cells. These findings enhance our understanding of the miRNAs involved in the process of neurogenesis and, in particular, highlight an important role of miR-664a-5p in SH-SY5Y cell neuronal differentiation. Further studies will be required to confirm the function of miR-664-5p in neuronal development and disease and to identify its relevant target genes.

Comparison of mitochondrial gene expression and polysome loading in different tobacco tissues

BackgroundTo investigate translational regulation of gene expression in plant mitochondria, a mitochondrial polysome isolation protocol was established for tobacco to investigate polysomal mRNA loading as a proxy for translational activity. Furthermore, we developed an oligonucleotide based microarray platform to determine the level of Nicotiana tabacum and Arabidopsis thaliana mitochondrial mRNA.ResultsMicroarray analysis of free and polysomal mRNAs was used to characterize differences in the levels of free transcripts and ribosome-bound mRNAs in various organs of tobacco plants. We have observed higher mitochondrial transcript levels in young leaves, flowers and floral buds as compared to fully expanded leaves and roots. A similar pattern of abundance was observed for ribosome-bound mitochondrial mRNAs in these tissues. However, the accumulation of the mitochondrial protein COX2 was found to be inversely related to that of its ribosome-bound mRNA.ConclusionsOur results indicate that the association of mitochondrial mRNAs to ribosomes is largely determined by the total transcript level of a gene. However, at least for Cox2, we demonstrated that the level of ribosome-bound mRNA is not reflected by the amount of COX2 protein.

The 3′-untranslated region of mRNAs as a site for ribozyme cleavage-dependent processing and control in bacteria

ABSTRACTBesides its primary informational role, the sequence of the mRNA (mRNA) including its 5′- and 3′- untranslated regions (UTRs), contains important features that are relevant for post-transcriptional and translational regulation of gene expression. In this work a number of bacterial twister motifs are characterized both in vitro and in vivo. The analysis of their genetic contexts shows that these motifs have the potential of being transcribed as part of polycistronic mRNAs, thus we suggest the involvement of bacterial twister motifs in the processing of mRNA. Our data show that the ribozyme-mediated cleavage of the bacterial 3′-UTR has major effects on gene expression. While the observed effects correlate weakly with the kinetic parameters of the ribozymes, they show dependence on motif-specific structural features and on mRNA stabilization properties of the secondary structures that remain on the 3′-UTR after ribozyme cleavage. Using these principles, novel artificial twister-based riboswitches are developed that exert their activity via ligand-dependent cleavage of the 3′-UTR and the removal of the protective intrinsic terminator. Our results provide insights into possible biological functions of these recently discovered and widespread catalytic RNA motifs and offer new tools for applications in biotechnology, synthetic biology and metabolic engineering.

Regulatory 3' Untranslated Regions of Bacterial mRNAs.

The untranslated regions (UTRs) of mRNA contain important features that are relevant to the post-transcriptional and translational regulation of gene expression. Most studies of bacterial UTRs have focused on the 5′regions; however, 3′UTRs have recently emerged as a new class of post-transcriptional regulatory elements. 3′UTRs were found to regulate the decay and translation initiation in their own mRNAs. In addition, 3′UTRs constitute a rich reservoir of small regulatory RNAs, regulating target gene expression. In the current review, we describe several recently discovered examples of bacterial regulatory 3′UTRs, discuss their modes of action, and illustrate how they facilitate gene regulation in various environments.

Analysis of translation using polysome profiling

During the past decade, there has been growing interest in the role of translational regulation of gene expression in many organisms. Polysome profiling has been developed to infer the translational status of a specific mRNA species or to analyze the translatome, i.e. the subset of mRNAs actively translated in a cell. Polysome profiling is especially suitable for emergent model organisms for which genomic data are limited. In this paper, we describe an optimized protocol for the purification of sea urchin polysomes and highlight the critical steps involved in polysome purification. We applied this protocol to obtain experimental results on translational regulation of mRNAs following fertilization. Our protocol should prove useful for integrating the study of the role of translational regulation in gene regulatory networks in any biological model. In addition, we demonstrate how to carry out high-throughput processing of polysome gradient fractions, for the simultaneous screening of multiple biological conditions and large-scale preparation of samples for next-generation sequencing.

RNA-binding proteins in mouse male germline stem cells: a mammalian perspective

Adult stem cells that reside in particular types of tissues are responsible for tissue homeostasis and regeneration. Cellular functions of adult stem cells are intricately related to the gene expression programs in those cells. Past research has demonstrated that regulation of gene expression at the transcriptional level can decisively alter cell fate of stem cells. However, cellular contents of mRNAs are sometimes not equivalent to proteins, the functional units of cells. It is increasingly realized that post-transcriptional and translational regulation of gene expression are also fundamental for stem cell functions. Compared to differentiated somatic cells, effects on cellular status manifested by varied expression of RNA-binding proteins and global protein synthesis have been demonstrated in several stem cell systems. Through the cooperation of both cis-elements of mRNAs and trans-acting RNA-binding proteins that are intimately associated with them, regulation of localization, stability, and translational status of mRNAs directly influences the self-renewal and differentiation of stem cells. Previous studies have uncovered some of the molecular mechanisms that underlie the functions of RNA-binding proteins in stem cells in invertebrate species. However, their roles in adult stem cells in mammals are just beginning to be unveiled. This review highlights some of the RNA-binding proteins that play important functions during the maintenance and differentiation of mouse male germline stem cells, the adult stem cells in the male reproductive organ.

Post-transcriptional regulation in budding yeast meiosis.

The precise regulation of gene expression is essential for developmental processes in eukaryotic organisms. As an important post-transcriptional regulatory point, translational control is complementary to transcriptional regulation. Sporulation in the budding yeast Saccharomyces cerevisiae is a developmental process controlled by a well-studied transcriptional cascade that drives the cell through the events of DNA replication, meiotic chromosome segregation, and spore assembly. Recent studies have revealed that as cells begin the meiotic divisions, translational regulation of gene expression fine tunes this transcriptional cascade. The significance and mechanisms of this translational regulation are beginning to emerge. These studies may also provide insights into translational regulation in germ cell development of multicellular organisms.

Translational regulation of gene expression by Lin28 and Roquin

Translational regulation of gene expression by Lin28 and Roquin

Tunable Riboregulator Switches for Post-transcriptional Control of Gene Expression.

Until recently, engineering strategies for altering gene expression have focused on transcription control using strong inducible promoters or one of several methods to knock down wasteful genes. Recently, synthetic riboregulators have been developed for translational regulation of gene expression. Here, we report a new modular synthetic riboregulator class that has the potential to finely tune protein expression and independently control the concentration of each enzyme in an engineered metabolic pathway. This development is important because the most straightforward approach to altering the flux through a particular metabolic step is to increase or decrease the concentration of the enzyme. Our design includes a cis-repressor at the 5' end of the mRNA that forms a stem-loop helix, occluding the ribosomal binding sequence and blocking translation. A trans-expressed activating-RNA frees the ribosomal-binding sequence, which turns on translation. The overall architecture of the riboregulators is designed using Watson-Crick base-pairing stability. We describe here a cis-repressor that can completely shut off translation of antibiotic-resistance reporters and a trans-activator that restores translation. We have established that it is possible to use these riboregulators to achieve translational control of gene expression over a wide dynamic range. We have also found that a targeting sequence can be modified to develop riboregulators that can, in principle, independently regulate translation of many genes. In a selection experiment, we demonstrated that by subtly altering the sequence of the trans-activator it is possible to alter the ratio of the repressed and activated states and to achieve intermediate translational control.

164 Translational regulation of gene expression in cardiomyocytes following exposure to oxidative stress

<h3></h3> Myocardial infarction leads to ischemia/reperfusion injury associated with an increase in oxidative stress. The cardiomyocyte response to oxidative stress is concentration-dependent: low concentrations may be protective, moderate levels promote apoptosis, and high levels lead to necrosis. These responses are associated with differential effects on cardiomyocyte mRNA expression. At the protein level, increasing levels of oxidative stress inhibit global protein synthesis, but some proteins continue to be synthesised. We investigated the effects of moderate and low levels of oxidative stress on translational regulation of mRNAs in cardiomyocytes. Total RNA and RNA associated with polysomes (i.e. mRNAs that are actively translated) were prepared from rat neonatal cardiomyocytes with or without treatment with H₂O₂ (0.2 mM, 1 h). RNA expression profiling was performed using Affymetrix microarrays and analysed using GeneSpring GX 13. 35 RNAs were significantly changed (&gt;1.5 fold; p &lt; 0.05, moderated T test with Benjamini and Hochberg false discovery rate correction) in the polysomes in response to H₂O₂, with a significant difference in the degree of change in polysomal vs total RNA. Of these, 9 were increased to a greater extent in the polysomes (indicative of selective translation) including the small G protein Rasd1 and the transcription factor Nfil3. Other mRNAs were not significantly different between polysomal and total RNA (e.g. Atf3, Hmox1), whereas genes such as Mdm2 were upregulated to a greater extent in the total RNA pool. Microarray data were validated by quantitative PCR. Data for all genes studied were consistent with the microarrays. In cardiomyocytes exposed to moderate oxidative stress (0.2 mM H₂O₂) or lower oxidative stress (0.1 mM H₂O₂), Rasd1 and Nfil3 were upregulated to a greater extent in the polysomes and Hmox1 showed a similar degree of upregulation in polysomal and total RNA pools. However, although Mdm2 mRNA was increased to a greater extent in the total pool with 0.2 mM H₂O₂, it was increased to a similar extent in polysomal and total RNA pools with 0.1 mM H₂O₂. Furthermore, although Atf3 mRNA was similarly upregulated in total and polysomal RNA pools with 0.2 mM H₂O₂, there was greater upregulation in the polysomes with 0.1 mM H₂O₂. Rasd1 protein was studied in cardiomyocytes exposed H₂O₂. Consistent with the mRNA expression data, Rasd1 was upregulated over ˜2 h. Thus, oxidative stress has concentration-dependent effects on protein translation of specific mRNAs. Rasd1 is of particular interest because it is associated with circadian rhythm regulation that may influence the response to myocardial infarction. Furthermore, a genetic polymorphism in the Rasd1 gene is associated with coronary artery disease and ischaemic stroke.

Translational regulation shapes the molecular landscape of complex disease phenotypes.

The extent of translational control of gene expression in mammalian tissues remains largely unknown. Here we perform genome-wide RNA sequencing and ribosome profiling in heart and liver tissues to investigate strain-specific translational regulation in the spontaneously hypertensive rat (SHR/Ola). For the most part, transcriptional variation is equally apparent at the translational level and there is limited evidence of translational buffering. Remarkably, we observe hundreds of strain-specific differences in translation, almost doubling the number of differentially expressed genes. The integration of genetic, transcriptional and translational data sets reveals distinct signatures in 3′UTR variation, RNA-binding protein motifs and miRNA expression associated with translational regulation of gene expression. We show that a large number of genes associated with heart and liver traits in human genome-wide association studies are primarily translationally regulated. Capturing interindividual differences in the translated genome will lead to new insights into the genes and regulatory pathways underlying disease phenotypes.