Function Of Human Proteins Research Articles

Pathogenicity classification of missense mutations based on deep generative model

Missense mutations affect the function of human proteins and are closely associated with multiple acute and chronic diseases. The identification of disease-associated missense mutations and their classification for pathogenicity can provide insights into the genetic basis of disease and protein function. This paper proposes MLAE (Method based on LSTM-Ladder AutoEncoder), a deep learning classification model for identifying disease-associated missense mutations and classifying their pathogenicity based on the Variational AutoEncoder (VAE) framework. MLAE overcomes the limitations of the VAE framework by introducing the Ladder structure, combined with LSTM networks. This reduces the loss of original information during the transmission process, thereby making the model more effective in learning. In the experiment, MLAE classified all 27572 possible missense variants of the three input proteins with an average classification AUC of 0.941. This result provides evidence that MLAE is effective in predicting pathogenicity. Additionally, MLAE provides results for multi-label classification, with an average Hamming loss of 0.196, supporting the classification of complex variants. The proposed MLAE method provides an insightful approach to effectively capture amino acid sequence information and accurately predict the pathogenicity of mutations, thereby providing an analytical basis for the study and prevention of related diseases.

GPATCH4 regulates rRNA and snRNA 2'-O-methylation in both DHX15-dependent and DHX15-independent manners.

Regulation of RNA helicase activity, often accomplished by protein cofactors, is essential to ensure target specificity within the complex cellular environment. The largest family of RNA helicase cofactors are the G-patch proteins, but the cognate RNA helicases and cellular functions of numerous human G-patch proteins remain elusive. Here, we discover that GPATCH4 is a stimulatory cofactor of DHX15 that interacts with the DEAH box helicase in the nucleolus via residues in its G-patch domain. We reveal that GPATCH4 associates with pre-ribosomal particles, and crosslinks to the transcribed ribosomal DNA locus and precursor ribosomal RNAs as well as binding to small nucleolar- and small Cajal body-associated RNAs that guide rRNA and snRNA modifications. Loss of GPATCH4 impairs 2'-O-methylation at various rRNA and snRNA sites leading to decreased protein synthesis and cell growth. We demonstrate that the regulation of 2'-O-methylation by GPATCH4 is both dependent on, and independent of, its interaction with DHX15. Intriguingly, the ATPase activity of DHX15 is necessary for efficient methylation of DHX15-dependent sites, suggesting a function of DHX15 in regulating snoRNA-guided 2'-O-methylation of rRNA that requires activation by GPATCH4. Overall, our findings extend knowledge on RNA helicase regulation by G-patch proteins and also provide important new insights into the mechanisms regulating installation of rRNA and snRNA modifications, which are essential for ribosome function and pre-mRNA splicing.

Proteomic approach to investigate the expression, localization, and functions of the protein product of the <i>SOWAHD</i> gene during granulocytic differentiation

Cataloging human proteins, determining their level of content, cellular localization, function performed, and potential medical significance are important tasks facing the global proteomic community. At present, the localization and functions of protein products for almost half of the protein-coding genes are unknown or poorly understood. The study of the organelle proteome is a promising approach to reveal the localization and functions of human proteins. The nuclear proteome is of particular interest because many nuclear-localized proteins, such as transcription factors, perform regulatory functions that determine cell fate. According to the results of a meta-analysis of the nuclear proteome, or nucleome, of HL-60 cells treated by all-trans-retinoic acid (ATRA), it was revealed that the function and localization of the protein product of the SOWAHD gene is poorly understood, in addition, there is no comprehensive information on the expression of SOWAHD at the protein level. In HL-60 cells for the protein-coding gene SOWAHD, mRNA expression was determined at the level of 6.4 ± 0.7 transcripts per million molecules. Using targeted mass spectrometry, the content of SOWAHD protein was measured in the range of 0.27-1.25 fmol/µg of total protein. Using stable isotope pulse-chase labeling, the half-life for the protein product of the SOWAHD gene was determined to be approximately 19 h. Proteomic profiling of the nuclear fraction of HL-60 cells showed that the SOWAHD protein content increased during ATRA-induced granulocytic differentiation, peaking at 9 h after the addition of the inductor and followed by a decrease at later time points. The results of the study indicate for the first time the nuclear localization and involvement of the protein product of the SOWAHD gene in induced granulocytic differentiation.

Proteomic Approach to Investigating Expression, Localization, and Functions of the SOWAHD Gene Protein Product during Granulocytic Differentiation.

Cataloging human proteins and evaluation of their expression, cellular localization, functions, and potential medical significance are important tasks for the global proteomic community. At present, localization and functions of protein products for almost half of protein-coding genes remain unknown or poorly understood. Investigation of organelle proteomes is a promising approach to uncovering localization and functions of human proteins. Nuclear proteome is of particular interest because many nuclear proteins, e.g., transcription factors, regulate functions that determine cell fate. Meta-analysis of the nuclear proteome, or nucleome, of HL-60 cells treated with all-trans-retinoic acid (ATRA) has shown that the functions and localization of a protein product of the SOWAHD gene are poorly understood. Also, there is no comprehensive information on the SOWAHD gene expression at the protein level. In HL-60 cells, the number of mRNA transcripts of the SOWAHD gene was determined as 6.4 ± 0.7 transcripts per million molecules. Using targeted mass spectrometry, the content of the SOWAHD protein was measured as 0.27 to 1.25 fmol/μg total protein. The half-life for the protein product of the SOWAHD gene determined using stable isotope pulse-chase labeling was ~19 h. Proteomic profiling of the nuclear fraction of HL-60 cells showed that the content of the SOWAHD protein increased during the ATRA-induced granulocytic differentiation, reached the peak value at 9 h after ATRA addition, and then decreased. Nuclear location and involvement of the SOWAHD protein in the ATRA-induced granulocytic differentiation have been demonstrated for the first time.

Uncharacterized protein C17orf80 - a novel interactor of human mitochondrial nucleoids.

Molecular functions of many human proteins remain unstudied, despite the demonstrated association with diseases or pivotal molecular structures, such as mitochondrial DNA (mtDNA). This small genome is crucial for the proper functioning of mitochondria, the energy-converting organelles. In mammals, mtDNA is arranged into macromolecular complexes called nucleoids that serve as functional stations for its maintenance and expression. Here, we aimed to explore an uncharacterized protein C17orf80, which was previously detected close to the nucleoid components by proximity labelling mass spectrometry. To investigate the subcellular localization and function of C17orf80, we took advantage of immunofluorescence microscopy, interaction proteomics and several biochemical assays. We demonstrate that C17orf80 is a mitochondrial membrane-associated protein that interacts with nucleoids even when mtDNA replication is inhibited. In addition, we show that C17orf80 is not essential for mtDNA maintenance and mitochondrial gene expression in cultured human cells. These results provide a basis for uncovering the molecular function of C17orf80 and the nature of its association with nucleoids, possibly leading to new insights about mtDNA and its expression.

Lysosomal LAMP proteins regulate lysosomal pH by direct inhibition of the TMEM175 channel

Maintaining a highly acidic lysosomal pH is central to cellular physiology. Here, we use functional proteomics, single-particle cryo-EM, electrophysiology, and invivo imaging to unravel a key biological function of human lysosome-associated membrane proteins (LAMP-1 and LAMP-2) in regulating lysosomal pH homeostasis. Despite being widely used as a lysosomal marker, the physiological functions of the LAMP proteins have long been overlooked. We show that LAMP-1 and LAMP-2 directly interact with and inhibit the activity of the lysosomal cation channel TMEM175, a key player in lysosomal pH homeostasis implicated in Parkinson's disease. This LAMP inhibition mitigates the proton conduction of TMEM175 and facilitates lysosomal acidification to a lower pH environment crucial for optimal hydrolase activity. Disrupting the LAMP-TMEM175 interaction alkalinizes the lysosomal pH and compromises the lysosomal hydrolytic function. In light of the ever-increasing importance of lysosomes to cellular physiology and diseases, our data have widespread implications for lysosomal biology.

Contrastive learning in protein language space predicts interactions between drugs and protein targets

Sequence-based prediction of drug-target interactions has the potential to accelerate drug discovery by complementing experimental screens. Such computational prediction needs to be generalizable and scalable while remaining sensitive to subtle variations in the inputs. However, current computational techniques fail to simultaneously meet these goals, often sacrificing performance of one to achieve the others. We develop a deep learning model, ConPLex, successfully leveraging the advances in pretrained protein language models ("PLex") and employing a protein-anchored contrastive coembedding ("Con") to outperform state-of-the-art approaches. ConPLex achieves high accuracy, broad adaptivity to unseen data, and specificity against decoy compounds. It makes predictions of binding based on the distance between learned representations, enabling predictions at the scale of massive compound libraries and the human proteome. Experimental testing of 19 kinase-drug interaction predictions validated 12 interactions, including four with subnanomolar affinity, plus a strongly binding EPHB1 inhibitor (KD = 1.3 nM). Furthermore, ConPLex embeddings are interpretable, which enables us to visualize the drug-target embedding space and use embeddings to characterize the function of human cell-surface proteins. We anticipate that ConPLex will facilitate efficient drug discovery by making highly sensitive in silico drug screening feasible at the genome scale. ConPLex is available open source at https://ConPLex.csail.mit.edu.

PUF: A potential repressor of oncogenes.

e15095 Background: RNA-binding proteins (RBPs) play a crucial role in orchestrating the function of RNAs. The regulation of RBPs is critical in various biological processes, including tumorigenesis. The PUF (Pumilio/FBF) RBPs are of particular interest due to their function in stem cells and tumor-initiating cells. Its has been shown that PUF proteins inhibit the translation of target genes by binding to a regulatory element (PBE) in the 3’ untranslated regions (3’UTRs) of their target mRNA. PUF proteins are required to maintain normal stem cells and potentially inhibit the formation of tumor-initiating cells by repressing the expression of oncogenes. Bioinformatics analysis has identified many oncogenes as potential targets of PUF, and pilot studies have confirmed that ERK, p38, JAK2, RUNX2, and RET mRNAs specifically interact with PUF protein. The objective of this study is to investigate the function of human PUF proteins in the initiation and progression of cancer cells. Methods: In worms (C. elegans), 100 % PUF mutants form tumors. Bioinformatics were performed to identify PUF target genes, it specifically binds UGUAnAUA sequences on target mRNA 3'UTRs. Yeast three-hybrid assay were performed to test the physical interaction between PUF protein and its target mRNA. The novel function of human PUF proteins in the initiation and progression of cancer cells was investigated using CRISPR/Cas9 knockout cancer cell lines and western Blot/IHC was done to determine their expression. Results: The results of the study showed that PUF proteins play a crucial role in inhibiting the formation of tumor-initiating cells. Loss of PUF function and activation of ERK signaling were found to promote the formation of these cells. Bioinformatics analysis revealed that many oncogenes are potential targets for PUF repression. The study also demonstrated that PUF represses the expression of ERK and p38 mRNAs via their 3’UTRs. These findings suggest that PUF may have therapeutic potential as a target for cancer treatment. Conclusions: In worms and human cells, normal PUF proteins promote the cell proliferation of stem cells, however, stem cells begin to differentiate, PUF proteins are required to complete differentiation. Therefore, in the differentiating cells, PUF mutation cannot complete differentiation, instead, return to undifferentiating cells, resulting in tumors. Bioinformatics and biochemical analyses revealed that many PUF repressing targets (~ > 30%) are oncogene and some labs including us found that PUF knockdown enhanced oncogene expression. PUF can be a potential biomarker, as low PUF expression may initiate tumors. Therapeutically, conditional PUF expression in tumor-initiating cells may suppress tumor progression by suppressing oncogene.

Molecular mechanisms of the Polycomblike family proteins in epigenetic regulation and their biological functions

<p indent="0mm">The PRC2 complex is a major complex in the Polycomb group of proteins. It plays an essential role in cell proliferation, differentiation, and the maintenance of cellular identity. PRC2 functions in gene repression mainly by modifying chromatin and regulating chromatin structure, among which the tri-methylation mark on histone H3 at Lys27 (H3K27me3) added by EZH2, the core PRC2 component, is a hallmark of gene repression. PRC2 core components must bind PRC2-associated proteins to form a holo-enzyme and become fully active. PRC2-associated proteins, such as Polycomblike (PCL) proteins, are important in regulating the function of PRC2. Recent studies have revealed that human PCL proteins play key roles in regulating the activity and the recruitment of chromatin by PRC2. In addition, PCL proteins are closely related to several human cancers. Thus, advances in the structure and function of PCL proteins would facilitate our understanding of their roles in PRC2 regulation and would expedite the development of strategies for therapeutically targeting PCL-related cancers. In this review, we summarize recent progress on the structure and function of PCL proteins, with an emphasis on the molecular mechanisms and biological functions of human PCL proteins.

Plasminogen and plasmin can bind to human T cells and generate truncated CCL21 that increases dendritic cell chemotactic responses

Plasmin is a broad-spectrum protease and therefore needs to be tightly regulated. Active plasmin is formed from plasminogen, which is found in high concentrations in the blood and is converted by the plasminogen activators. In the circulation, high levels of α2-antiplasmin rapidly and efficiently inhibit plasmin activity. Certain myeloid immune cells have been shown to bind plasmin and plasminogen on their cell surface via proteins that bind to the plasmin(ogen) kringle domains. Our earlier work showed that T cells can activate plasmin but that they do not themselves express plasminogen. Here, we demonstrate that T cells express several known plasminogen receptors and that they bind plasminogen on their cell surface. We show T cell–bound plasminogen was converted to plasmin by plasminogen activators upon T cell activation. To examine functional consequences of plasmin generation by activated T cells, we investigated its effect on the chemokine, C-C motif chemokine ligand 21 (CCL21). Video microscopy and Western blotting confirmed that plasmin bound by human T cells cleaves CCL21 and increases the chemotactic response of monocyte-derived dendritic cells toward higher CCL21 concentrations along the concentration gradient by increasing their directional migration and track straightness. These results demonstrate how migrating T cells and potentially other activated immune cells may co-opt a powerful proteolytic system from the plasma toward immune processes in the peripheral tissues, where α2-antiplasmin is more likely to be absent. We propose that plasminogen bound to migrating immune cells may strongly modulate chemokine responses in peripheral tissues.

Comparative analysis of web-based programs for single amino acid substitutions in proteins

Single amino-acid substitution in a protein affects its structure and function. These changes are the primary reasons for the advent of many complex diseases. Analyzing single point mutations in a protein is crucial to see their impact and to understand the disease mechanism. This has given many biophysical resources, including databases and web-based tools to explore the effects of mutations on the structure and function of human proteins. For a given mutation, each tool provides a score-based outcomes which indicate deleterious probability. In recent years, developments in existing programs and the introduction of new prediction algorithms have transformed the state-of-the-art protein mutation analysis. In this study, we have performed a systematic study of the most commonly used mutational analysis programs (10 sequence-based and 5 structure-based) to compare their prediction efficiency. We have carried out extensive mutational analyses using these tools for previously known pathogenic single point mutations of five different proteins. These analyses suggested that sequence-based tools, PolyPhen2, PROVEAN, and PMut, and structure-based web tool, mCSM have a better prediction accuracy. This study indicates that the employment of more than one program based on different approaches should significantly improve the prediction power of the available methods.

Probing terahertz dynamics of multidomain protein in cell-like confinement

The development of meaningful descriptions of multidomain proteins exhibiting complex inter-domain dynamics modes is a key challenge for understanding their roles in molecular recognition and signalling processes. Here we developed a generally applicable approach for probing the low frequency collective hydration dynamics of multidomain proteins that uses terahertz spectroscopy of a protein molecule confined in a phospholipid reverse micelles environment (named Droplet THz). With the combination of normal mode analysis, we demonstrated the binding of calcium ions modulates the local inter-domain motion of the human coagulant factor VIII protein in a concentration-dependent manner. These findings highlight the Droplet THz as a valuable tool for dissecting the ultrafast dynamics of domain motion in the multidomain proteins and suggest a modulating mechanism of calcium ions on the structural flexibility and function of human coagulant proteins.

Developing large-scale molecular stability engines for clinical variant interpretation

Computational models that aim to predict the impact of an amino acid substitution on the structure and function of human proteins using molecular stability considerations are widely available (for example, SIFT and Polyphen2). In clinical missense variant interpretation however, these models are typically considered to have too weak a predictive value to be of high utility. However, when there is sufficient protein structure data and feature support for a given transcript, a model using a molecular stability engine (MSE) can reach a predictive value high enough to be used in clinical variant interpretation.

Human disease-associated extracellular matrix orthologs ECM3 and QBRICK regulate primary mesenchymal cell migration in sea urchin embryos.

Sea urchin embryos have been one of model organisms to investigate cellular behaviors because of their simple cell composition and transparent body. They also give us an opportunity to investigate molecular functions of human proteins of interest that are conserved in sea urchin. Here we report that human disease-associated extracellular matrix orthologues ECM3 and QBRICK are necessary for mesenchymal cell migration during sea urchin embryogenesis. Immunofluorescence has visualized the colocalization of QBRICK and ECM3 on both apical and basal surface of ectoderm. On the basal surface, QBRICK and ECM3 constitute together a mesh-like fibrillar structure along the blastocoel wall. When the expression of ECM3 was knocked down by antisense-morpholino oligonucleotides, the ECM3-QBRICK fibrillar structure completely disappeared. When QBRICK was knocked down, the ECM3 was still present, but the basally localized fibers became fragmented. The ingression and migration of primary mesenchymal cells were not critically affected, but their migration at later stages was severely affected in both knock-down embryos. As a consequence of impaired primary mesenchymal cell migration, improper spicule formation was observed. These results indicate that ECM3 and QBRICK are components of extracellular matrix, which play important role in primary mesenchymal cell migration, and that sea urchin is a useful experimental animal model to investigate human disease-associated extracellular matrix proteins.

Humanized Drosophila Model of the Meier-Gorlin Syndrome Reveals Conserved and Divergent Features of the Orc6 Protein.

Meier-Gorlin syndrome (MGS) is a rare, autosomal recessive disorder characterized by microtia, primordial dwarfism, small ears, and skeletal abnormalities. Patients with MGS often carry mutations in genes encoding the subunits of the Origin Recognition Complex (ORC), components of the prereplicative complex and replication machinery. Orc6 is an important component of ORC and has functions in both DNA replication and cytokinesis. A mutation in the conserved C-terminal motif of Orc6 associated with MGS impedes the interaction of Orc6 with core ORC. Recently, a new mutation in Orc6 was also identified; however, it is localized in the N-terminal domain of the protein. To study the functions of Orc6, we used the human gene to rescue the orc6 deletion in Drosophila Using this "humanized" Orc6-based Drosophila model of MGS, we discovered that unlike the previous Y225S MGS mutation in Orc6, the K23E substitution in the N-terminal TFIIB-like domain of Orc6 disrupts the protein ability to bind DNA. Our studies revealed the importance of evolutionarily conserved and variable domains of Orc6 protein, and allowed the studies of human protein functions and the analysis of the critical amino acids in live animal heterologous system, as well as provided novel insights into the mechanisms underlying MGS pathology.

Global view of human protein glycosylation pathways and functions

Glycosylation is the most abundant and diverse form of post-translational modification of proteins that is common to all eukaryotic cells. Enzymatic glycosylation of proteins involves a complex metabolic network and different types of glycosylation pathways that orchestrate enormous amplification of the proteome in producing diversity of proteoforms and its biological functions. The tremendous structural diversity of glycans attached to proteins poses analytical challenges that limit exploration of specific functions of glycosylation. Major advances in quantitative transcriptomics, proteomics and nuclease-based gene editing are now opening new global ways to explore protein glycosylation through analysing and targeting enzymes involved in glycosylation processes. In silico models predicting cellular glycosylation capacities and glycosylation outcomes are emerging, and refined maps of the glycosylation pathways facilitate genetic approaches to address functions of the vast glycoproteome. These approaches apply commonly available cell biology tools, and we predict that use of (single-cell) transcriptomics, genetic screens, genetic engineering of cellular glycosylation capacities and custom design of glycoprotein therapeutics are advancements that will ignite wider integration of glycosylation in general cell biology.

Predicting Functions of Uncharacterized Human Proteins: From Canonical to Proteoforms.

Despite tremendous efforts in genomics, transcriptomics, and proteomics communities, there is still no comprehensive data about the exact number of protein-coding genes, translated proteoforms, and their function. In addition, by now, we lack functional annotation for 1193 genes, where expression was confirmed at the proteomic level (uPE1 proteins). We re-analyzed results of AP-MS experiments from the BioPlex 2.0 database to predict functions of uPE1 proteins and their splice forms. By building a protein–protein interaction network for 12 ths. identified proteins encoded by 11 ths. genes, we were able to predict Gene Ontology categories for a total of 387 uPE1 genes. We predicted different functions for canonical and alternatively spliced forms for four uPE1 genes. In total, functional differences were revealed for 62 proteoforms encoded by 31 genes. Based on these results, it can be carefully concluded that the dynamics and versatility of the interactome is ensured by changing the dominant splice form. Overall, we propose that analysis of large-scale AP-MS experiments performed for various cell lines and under various conditions is a key to understanding the full potential of genes role in cellular processes.

Testing for Ketoprofen Binding to HSA Coated Magnetic Nanoparticles under Normal Conditions and after Oxidative Stress.

Binding and transport of ligands is one of the most important functions of human blood serum proteins. Human serum albumin is found in plasma at the highest concentration. Because of this, it is important to study protein–drug interactions for this albumin. Since there is no single model describing this interaction, it is necessary to measure it for each active substance. Drug binding should also be studied in conditions that simulate pathological conditions of the body, i.e., after oxidative stress. Due to this, it is expected that the methods for testing these interactions need to be easy and fast. In this study, albumin immobilized on magnetic nanoparticles was successfully applied in the study of protein–drug binding. Ketoprofen was selected as a model drug and interactions were tested under normal conditions and artificially induced oxidative stress. The quality of obtained results for immobilized protein was confirmed with those for free albumin and literature data. It was shown that the type of magnetic core coverage does not affect the quality of the obtained results. In summary, a new, fast, effective, and universal method for testing protein–drug interactions was proposed, which can be performed in most laboratories.

Emerging Functions of Human IFIT Proteins in Cancer.

Interferon-induced protein with tetratricopeptide repeats (IFIT) genes are prominent interferon-stimulated genes (ISGs). The human IFIT gene family consists of four genes named IFIT1, IFIT2, IFIT3, and IFIT5. The expression of IFIT genes is very low in most cell types, whereas their expression is greatly enhanced by interferon treatment, viral infection, and pathogen-associated molecular patterns (PAMPs). The proteins encoded by IFIT genes have multiple tetratricopeptide repeat (TPR) motifs. IFIT proteins do not have any known enzymatic roles. However, they execute a variety of cellular functions by mediating protein-protein interactions and forming multiprotein complexes with cellular and viral proteins through their multiple TPR motifs. The versatile tertiary structure of TPR motifs in IFIT proteins enables them to be involved in distinct biological functions, including host innate immunity, antiviral immune response, virus-induced translation initiation, replication, double-stranded RNA signaling, and PAMP recognition. The current understanding of the IFIT proteins and their role in cellular signaling mechanisms is limited to the antiviral immune response and innate immunity. However, recent studies on IFIT protein functions and their involvement in various molecular signaling mechanisms have implicated them in cancer progression and metastasis. In this article, we focused on critical molecular, biological and oncogenic functions of human IFIT proteins by reviewing their prognostic significance in health and cancer. Research suggests that IFIT proteins could be novel therapeutic targets for cancer therapy.

SA61 - THE ROLE OF MUSASHI RNA BINDING PROTEINS IN ASSOCIATIVE LEARNING AND MEMORY

Background The Musashi family of RNA binding proteins, MSI-1 and MSI-2, retain a pivotal role in stem cell maintenance, nervous system development and tumourigenesis. Recently, we demonstrated that the C. elegans sole ortholog, MSI-1, can regulate forgetting upon associative learning via a 3’ UTR dependent translational repression of the Arp2/3 actin branching complex. Based on these findings, here we opted to decipher the role of human MSI-1 and MSI-2 in the regulation of associative learning and memory; and investigated whether a conserved mechanism of action exists across species. Methods Based on the homology shared between the human and nematode musashi proteins, we first constructed two transgenic C. elegans lines expressing the human proteins in an msi-1 knockout background by using molecular genetic techniques. Moreover, learning and memory (both short-term and long-term) phenotypes were assessed in a paradigm known as negative olfactory chemotaxis assay. Following, using pharmacological manipulations, the function of human musashi proteins were studied both on the molecular and behavioral level. Results Introduction of both human MSI-1 and MSI-2 proteins fully rescued the previously seen forgetting defect of msi-1 (lf) mutant worms, during C. elegans aversive olfactory short-term and long-term memory. Since musashi was shown to regulate gene expression at the translational level via its highly conserved RRM domain, we next sought to disrupt binding to its downstream targets and assessed the effects at the behavioral level. Pharmacological perturbation of both human MSI-1 and MSI-2 function suppressed the memory rescue phenotype previously observed; without causing locomotion, chemotaxis or learning deficits. Discussion Taken together, our results support a conserved role of musashi in negative associative memory from nematodes to humans and might, ultimately, prove to be helpful in elucidating novel therapy targets for the treatment of memory-related disorders.