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Showing RARS1 — RARS is a alias.

RARS1

Arginine--tRNA ligase, cytoplasmic · UniProt P54136

Length
660 aa
Mass
75.4 kDa
Annotated
2026-06-10
43 papers in source corpus 10 papers cited in narrative 10 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 5/5 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

RARS1 encodes the cytoplasmic arginyl-tRNA synthetase (hArgRS), an aminoacyl-tRNA synthetase that charges arginine onto its cognate tRNA and functions as a subunit of the multisynthetase complex, a role tied to myelination (PMID:24777941, PMID:28905880). Biallelic RARS1 mutations cause hypomyelinating leukodystrophy through several distinct mechanisms: the R512Q substitution and a C-terminal frameshift disrupt enzyme structure and aminoacylation activity, whereas the most frequent c.5A>G (p.D2G) variant leaves catalysis intact but suppresses translation of hArgRS mRNA via an upstream open reading frame (PMID:33515434); other pathogenic substitutions reduce ArgRS protein expression and stability in patient cells (PMID:28905880, PMID:37186453). The HLD9-associated S456L mutation mislocalizes RARS1 into lysosomal aggregates, lowering lysosome-associated S6 ribosomal protein phosphorylation and blocking oligodendroglial differentiation (PMID:31737794). Integration of RARS1 into the multisynthetase complex is required for proper forebrain neurodevelopment, as forebrain-specific exclusion disrupts neural growth, behavior, and ribosomal/neurodevelopmental gene expression [PMID:bio_10.1101_2025.09.08.674979]. Beyond translation, RARS1 sequesters AIMP1 within the complex to prevent its secretion as the inflammatory cytokine EMAP II (PMID:17443684). Non-canonical and oncogenic roles have been described in cancer contexts, including a RARS1-MAD1L1 fusion that activates the FUBP1/c-Myc pathway in nasopharyngeal carcinoma (PMID:29133573).

Mechanistic history

Synthesis pass · year-by-year structured walk · 9 steps
  1. 2007 Medium

    Established a non-translational moonlighting function for RARS1: by binding AIMP1 within the multisynthetase complex it acts as a sequestering factor preventing AIMP1 release as a secreted cytokine.

    Evidence RARS1 overexpression in HeLa and MCF7 cells with measurement of AIMP1 secretion plus proteasome inhibition assay

    PMID:17443684

    Open questions at the time
    • Direct binding interface between RARS1 and AIMP1 not mapped
    • Physiological contexts where this sequestration is regulated not defined
  2. 2014 Medium

    Linked RARS1 to human disease for the first time, identifying it as a cause of hypomyelination and implicating the multisynthetase complex in myelination.

    Evidence Whole exome sequencing of hypomyelination patients with compound heterozygous mutations; clinical and MRI characterization

    PMID:24777941

    Open questions at the time
    • Did not establish how aminoacylation loss leads specifically to a myelin phenotype
    • No biochemical demonstration of mutant enzyme dysfunction
  3. 2016 Low

    Probed whether RARS1 expression is dynamically regulated under stress, showing its induction during neuronal ischemia.

    Evidence OGD ischemia model in primary neurons with time-course measurement of Rars transcription and ArgRS protein

    PMID:27465332

    Open questions at the time
    • Expression-level correlation only, no causal mechanism
    • Functional consequence of ArgRS upregulation in ischemia not tested
  4. 2017 Medium

    Provided the biochemical link between RARS1 mutations and disease by showing reduced ArgRS and multisynthetase complex levels and impaired arginine-dependent proliferation in patient cells.

    Evidence Western blot and Blue native-PAGE on patient fibroblasts plus proliferation assay under arginine limitation

    PMID:28905880

    Open questions at the time
    • Did not resolve whether loss is from instability or reduced synthesis
    • Mechanism connecting reduced aminoacylation to oligodendrocyte pathology unaddressed
  5. 2019 Medium

    Defined a localization-based pathogenic mechanism, connecting the S456L mutant to lysosomal mislocalization, reduced S6 phosphorylation, and a block in oligodendroglial differentiation.

    Evidence Localization imaging, subcellular fractionation, S6 phosphorylation western blot, and differentiation assay in FBD-102b oligodendroglial cells

    PMID:31737794

    Open questions at the time
    • Why mutant aggregates target lysosomes is unknown
    • Link between S6 phosphorylation and myelin formation correlative
  6. 2021 High

    Dissected genotype-specific pathogenic mechanisms, showing some mutations impair catalysis while the common c.5A>G variant instead suppresses translation through an upstream ORF.

    Evidence In vitro aminoacylation assays of recombinant hArgRS mutants, mutagenesis, and mRNA translation analysis

    PMID:33515434

    Open questions at the time
    • In vivo validation of uORF-mediated suppression not performed
    • Tissue-specific sensitivity of oligodendrocytes not explained
  7. 2023 Medium

    Extended the mutational spectrum by confirming that additional biallelic variants, including c.5A>T, reduce ArgRS expression and stability.

    Evidence Western blot for ArgRS expression and stability in patient-derived cells

    PMID:37186453

    Open questions at the time
    • Single-method protein readout
    • No catalytic activity assessment for these variants
  8. 2025 Medium

    Demonstrated that RARS1's incorporation into the multisynthetase complex, not merely its presence, is required for neurodevelopment, causally linking complex integration to forebrain growth and behavior.

    Evidence Conditional forebrain-specific mouse knockout with behavioral testing, transcriptomics, and colocalization imaging (preprint)

    PMID:bio_10.1101_2025.09.08.674979

    Open questions at the time
    • Preprint, not yet peer-reviewed
    • Cell-type-specific contribution within forebrain not resolved
  9. 2025 Low

    Reported a non-canonical oncogenic function in hepatocellular carcinoma, where RARS1 stabilizes ENO1 and modulates PI3K/AKT/GSK3β signaling and ferroptosis.

    Evidence RARS1 knockdown, Co-IP for RARS1-ENO1, ubiquitination assay, and ferroptosis assays in LIHC cell lines

    PMID:41451236

    Open questions at the time
    • Single lab, abstract-level mechanistic detail awaiting independent replication
    • Direct RARS1-ENO1 binding interface not characterized

Open questions

Synthesis pass · forward-looking unresolved questions
  • It remains unresolved why an essential housekeeping aminoacylation enzyme produces a predominantly oligodendrocyte/neurodevelopmental phenotype, and how its canonical, sequestration, and putative oncogenic roles are mechanistically partitioned across tissues.
  • No structural model linking specific mutations to tissue selectivity
  • Causal pathway from arginylation deficit to myelin loss undefined
  • Reconciliation of moonlighting AIMP1/ENO1 functions with core synthetase role missing

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0016874 ligase activity 2 GO:0003723 RNA binding 1 GO:0140098 catalytic activity, acting on RNA 1 GO:0140313 molecular sequestering activity 1
Localization
GO:0005764 lysosome 1 GO:0005829 cytosol 1
Pathway
R-HSA-1266738 Developmental Biology 2 R-HSA-392499 Metabolism of proteins 2
Partners
AIMP1AIMP2ENO1
Complex memberships
multisynthetase complex

Evidence

Reading pass · 10 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2014 Mutations in RARS1 (encoding cytoplasmic arginyl-tRNA synthetase) cause hypomyelination; RARS1 protein is a subunit of the multisynthetase complex, which is implicated as a key player in myelination. Whole exome sequencing of patients with hypomyelination combined with identification of compound heterozygous mutations in RARS1; clinical and MRI characterization Annals of neurology Medium 24777941
2017 RARS1 protein levels and multisynthetase complex levels are significantly reduced (by 80% and 90% respectively) in patient fibroblasts carrying homozygous or compound heterozygous RARS1 mutations; patient fibroblasts show impaired proliferation under arginine-limited conditions, indicating inefficiency of protein synthesis (aminoacylation function). Western blotting and Blue native-PAGE on patient fibroblast extracts; fibroblast proliferation assay under arginine-limiting conditions European journal of human genetics Medium 28905880
2021 Disease-causing RARS1 mutations have distinct pathogenic mechanisms: the R512Q substitution and frameshift (ΔC/Y616Lfs*6) mutations impair the structure and aminoacylation activity of human cytoplasmic arginyl-tRNA synthetase (hArgRS), whereas the most frequent mutation c.5A>G (p.D2G) does not impair hArgRS aminoacylation activity but instead reduces translation of hArgRS mRNA, with an upstream open reading frame contributing to suppressed translation of the downstream main ORF. In vitro enzymatic activity assays of recombinant hArgRS mutants; mutagenesis; mRNA translation analysis; identification of upstream ORF effect on translation Science China. Life sciences High 33515434
2019 The HLD9-associated S456L missense mutation of RARS1 causes mislocalization of RARS1 protein as aggregates into lysosomes (rather than cytoplasmic distribution of wild-type), decreases lysosome-related S6 ribosomal protein phosphorylation (a signal required for myelin formation), and inhibits oligodendroglial morphological differentiation (failure to form myelin web-like structures) in FBD-102b oligodendroglial cells. Subcellular fractionation/localization imaging of wild-type vs. mutant RARS1 in cells; immunofluorescence; western blotting for S6 phosphorylation; oligodendroglial differentiation assay in FBD-102b cells Biochemistry and biophysics reports Medium 31737794
2023 Biallelic RARS1 mutations (c.1535G>A/p.Arg512Gln, c.1382G>A/p.Arg461His, and homozygous c.5A>T/p.Asp2Val) reduce ArgRS protein expression and stability in patient-derived cells, confirming pathogenicity; the c.5A>T variant affects expression similarly to c.5A>G. In vitro functional validation of RARS1 mutations; western blotting for ArgRS protein expression and stability in patient cells Epilepsia open Medium 37186453
2007 RARS1 (arginyl-tRNA synthetase) overexpression impairs secretion of AIMP1/EMAP II cytokine from HeLa and MCF7 cells, indicating that RARS1 binding to AIMP1 within the multisynthetase complex prevents AIMP1 secretion; proteasome inhibition impairs cleavage of AIMP1 to generate mature EMAP II. RARS1 overexpression in HeLa and MCF7 cells with measurement of AIMP1 secretion; proteasome inhibition assay Journal of cellular physiology Medium 17443684
2017 The RARS1-MAD1L1 fusion protein (resulting from chromosomal translocation) interacts with AIMP2, activating the FUBP1/c-Myc pathway to promote cancer stem cell-like properties and therapeutic resistance in nasopharyngeal carcinoma; silencing FUBP1 or inhibiting c-Myc abrogates these CSC-like characteristics. Co-immunoprecipitation; chromatin immunoprecipitation; MTT/colony/sphere formation assays; in vivo chemoresistance assay; siRNA silencing Clinical cancer research Medium 29133573
2025 Exclusion of RARS1 from the multisynthetase complex in the mouse forebrain causes profound disruptions in neural development (drastically reduced forebrain size and behavioral deficits), dysregulation of neurodevelopmental and ribosomal genes, and perturbation of RARS1 subcellular localization and colocalization with translational machinery components, demonstrating that RARS1 integration into the multisynthetase complex is required for proper neurodevelopment. Conditional forebrain-specific mouse knockout model; behavioral testing; transcriptomics; subcellular localization/colocalization imaging bioRxivpreprint Medium bio_10.1101_2025.09.08.674979
2025 RARS1 knockdown in hepatocellular carcinoma cells inhibits proliferation and migration, regulates the PI3K/AKT/GSK3β pathway, and suppresses ferroptosis via interaction with ENO1 (inhibiting ENO1 ubiquitination and degradation). RARS1 knockdown in LIHC cell lines; co-immunoprecipitation for RARS1-ENO1 interaction; ubiquitination assay; PI3K/AKT/GSK3β pathway analysis; ferroptosis assays Frontiers in immunology Low 41451236
2016 Ischemic injury induces upregulation of Rars transcriptional activity and ArgRS protein overexpression in primary cultured neurons (peaking at 6 h post-reoxygenation); ischemic preconditioning inhibits this increase, suggesting a regulatory role for RARS1 expression levels in neuronal ischemic response. OGD-based ischemia model in primary neurons; measurement of Rars transcriptional activity and ArgRS protein expression at multiple time points post-reoxygenation Journal of Huazhong University of Science and Technology. Medical sciences Low 27465332

Source papers

Stage 0 corpus · 43 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
1994 Function of the retinoic acid receptors (RARs) during development (II). Multiple abnormalities at various stages of organogenesis in RAR double mutants. Development (Cambridge, England) 803 7607068
1994 Function of the retinoic acid receptors (RARs) during development (I). Craniofacial and skeletal abnormalities in RAR double mutants. Development (Cambridge, England) 657 7607067
1993 RARs and RXRs: evidence for two autonomous transactivation functions (AF-1 and AF-2) and heterodimerization in vivo. The EMBO journal 303 8389696
2006 Refractory anemia with ringed sideroblasts associated with marked thrombocytosis (RARS-T), another myeloproliferative condition characterized by JAK2 V617F mutation. Blood 141 16741247
2009 Developmental expression of retinoic acid receptors (RARs). Nuclear receptor signaling 109 19471585
1990 Expression of retinoic acid receptor genes and the ligand-binding selectivity of retinoic acid receptors (RAR's). Biochemical and biophysical research communications 97 2154975
2014 Mutations in RARS cause hypomyelination. Annals of neurology 94 24777941
2012 Retinoic acid induces neurogenesis by activating both retinoic acid receptors (RARs) and peroxisome proliferator-activated receptor β/δ (PPARβ/δ). The Journal of biological chemistry 91 23105114
2001 F9 embryocarcinoma cells: a cell autonomous model to study the functional selectivity of RARs and RXRs in retinoid signaling. Histology and histopathology 72 11510982
2016 Predictors of survival in refractory anemia with ring sideroblasts and thrombocytosis (RARS-T) and the role of next-generation sequencing. American journal of hematology 62 26874914
1997 Specific activation of retinoic acid receptors (RARs) and retinoid X receptors reveals a unique role for RARgamma in induction of differentiation and apoptosis of S91 melanoma cells. The Journal of biological chemistry 62 9228081
1994 c-erbA alpha/T3R and RARs control commitment of hematopoietic self-renewing progenitor cells to apoptosis or differentiation and are antagonized by the v-erbA oncogene. Oncogene 61 7906409
2017 The RARS-MAD1L1 Fusion Gene Induces Cancer Stem Cell-like Properties and Therapeutic Resistance in Nasopharyngeal Carcinoma. Clinical cancer research : an official journal of the American Association for Cancer Research 52 29133573
1996 Inhibition of rabbit collagenase (matrix metalloproteinase-1; MMP-1) transcription by retinoid receptors: evidence for binding of RARs/RXRs to the -77 AP-1 site through interactions with c-Jun. Journal of cellular physiology 44 8908199
2001 Antagonists of retinoic acid receptors (RARs) are potent growth inhibitors of prostate carcinoma cells. British journal of cancer 40 11487280
2003 Retinoid receptors and vitamin A deficiency: differential patterns of transcription during early avian development and the rapid induction of RARs by retinoic acid. Developmental biology 38 12921748
2017 Mutations in RARS cause a hypomyelination disorder akin to Pelizaeus-Merzbacher disease. European journal of human genetics : EJHG 34 28905880
2022 Retinoic acid, RARs and early development. Journal of molecular endocrinology 33 35593389
2015 Refractory anemia with ring sideroblasts and RARS with thrombocytosis. American journal of hematology 33 25899435
2012 Improved survival with iron chelation therapy for red blood cell transfusion dependent lower IPSS risk MDS may be more significant in patients with a non-RARS diagnosis. Leukemia research 31 22921191
2005 Upregulation of connexin 43 by retinoids but not by non-provitamin A carotenoids requires RARs. Nutrition and cancer 19 16091010
2008 The role of JAK2 mutations in RARS and other MDS. Hematology. American Society of Hematology. Education Program 18 19074058
1994 Expression of the retinoic Acid nuclear receptors (rars) and retinoid x-receptor (rxr) genes in estrogen-receptor positive and negative breast-cancer. International journal of oncology 16 21566993
2003 Myelodysplastic syndrome (RARS) with +i(12p) abnormality in a patient 10 months after diagnosis and successful treatment of a mediastinal germ cell tumor (MGCT). Annals of hematology 15 14615911
2014 RARs and microRNAs. Sub-cellular biochemistry 14 24962885
2019 Hypomyelinating Leukodystrophy with Spinal Cord Involvement Caused by a Novel Variant in RARS: Report of Two Unrelated Patients. Neuropediatrics 13 30791064
2007 Proteasomes and RARS modulate AIMP1/EMAP II secretion in human cancer cell lines. Journal of cellular physiology 13 17443684
2016 Negative impact on clinical outcome of the mutational co-occurrence of SF3B1 and DNMT3A in refractory anemia with ring sideroblasts (RARS). Leukemia & lymphoma 12 27771989
2011 Proliferation of cells and expression of RARs, RXRs and HPV viral E6 and E7 proteins in cervical cancer cell lines after treatment with ATRA. Annals of agricultural and environmental medicine : AAEM 10 21736279
2021 Distinct pathogenic mechanisms of various RARS1 mutations in Pelizaeus-Merzbacher-like disease. Science China. Life sciences 9 33515434
2023 Circular RNA, circular RARS, promotes aerobic glycolysis of non-small-cell lung cancer by binding with LDHA. Thoracic cancer 8 36628612
2019 Hypomyelinating leukodystrophy-associated mutation of RARS leads it to the lysosome, inhibiting oligodendroglial morphological differentiation. Biochemistry and biophysics reports 8 31737794
2012 The granulocyte-colony stimulating factor receptor (G-CSFR) interacts with retinoic acid receptors (RARs) in the regulation of myeloid differentiation. Journal of leukocyte biology 8 23136256
2010 Chromosomes in a hybrid zone of Israeli mole rars (Spalax, Rodentia). Genetika 5 21250542
1996 Dexamethasone decreases the expression of retinoic acid receptors (RARs) in rat liver. The Journal of steroid biochemistry and molecular biology 5 8645624
2012 RARS with fibrosis and del(20q) transformed into ALL. Medical oncology (Northwood, London, England) 4 22760793
2023 RARS1-related developmental and epileptic encephalopathy. Epilepsia open 3 37186453
2003 Nucleolar abnormalities--a defect of the nucleolar preribosome assembly--in ringed sideroblasts in refractory anaemia with ringed sideroblasts (RARS) of myelodysplastic syndrome (MDS). An electron microscopic study. Sbornik lekarsky 3 14577129
2016 Ischemic preconditioning inhibits over-expression of arginyl-tRNA synthetase gene Rars in ischemia-injured neurons. Journal of Huazhong University of Science and Technology. Medical sciences = Hua zhong ke ji da xue xue bao. Yi xue Ying De wen ban = Huazhong keji daxue xuebao. Yixue Yingdewen ban 2 27465332
2004 Accumulation of homoplasmic mtDNA point mutations in erythroblasts isolated from the bone marrow of patients with refractory anemia with ring sideroblasts (RARS). Mitochondrion 2 16120395
1993 Progression of refractory anaemia with ringed sideroblasts (RARS) to B-acute lymphoblastic leukaemia. Haematologia 1 8157211
2025 RARS1 inhibits ENO1 ubiquitination and degradation to protect against ferroptosis in hepatocellular carcinoma. Frontiers in immunology 0 41451236
1996 Murine endodermal F9E cells, derived from the teratocarcinoma line F9, contain high basal levels of retinoic acid receptors (RARs and RXRs) but are not sensitive to the actions of retinoic acid. Differentiation; research in biological diversity 0 8765051

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