| 2009 |
LARP6 binds the conserved 5' stem-loop (5'SL) in the 5'UTR of type I collagen mRNAs (COL1A1 and COL1A2) in a sequence-specific manner with Kd of 1.4 nM, using a bipartite RNA binding domain (La motif + RRM). LARP6 does not associate with polysomes; overexpression blocks ribosomal loading on collagen mRNAs, while knockdown also decreases polysomal loading. LARP6 activity is required for focal (discrete ER-localized) synthesis of collagen polypeptides. |
RNA binding assay (Kd measurement), gel mobility shift, siRNA knockdown, polysome profiling, collagen-GFP reporter in cells |
Journal of molecular biology |
High |
19917293
|
| 2014 |
Structure of the La motif (LaM) and RRM1 of human LARP6 was solved, revealing considerable structural variation from the prototypic La protein. RNA recognition requires synergy between LaM, RRM1, and the interdomain linker. Mutagenesis guided by the structure showed that the interdomain linker and tandem domain dynamics are required for substrate selectivity toward the collagen 5'SL. |
X-ray crystallography, mutagenesis, NMR |
Nucleic acids research |
High |
25488812
|
| 2014 |
Five specific nucleotides within the single-stranded regions of the 5'SL are required for high-affinity LARP6 binding; mutation of individual nucleotides abolishes binding. LARP6 requires both the La domain (T133 critical for folding) and the RRM (loop 3 critical for 5'SL binding). Loop 3 of the RRM also mediates interaction with the protein translocation channel SEC61, and a LARP6 mutant that binds 5'SL but cannot interact with SEC61 suppresses collagen synthesis in a dominant-negative manner. |
Gel mobility shift assay, mutagenesis, Co-IP (LARP6–SEC61 interaction), dominant-negative overexpression |
RNA biology |
High |
25692237
|
| 2014 |
LARP6 associates with ER membranes and, together with nonmuscle myosin filaments, partitions collagen mRNAs to the ER membrane prior to signal peptide synthesis. Knockdown of LARP6 or depolymerization of nonmuscle myosin releases collagen mRNAs from the ER membrane and causes hypermodification, poor secretion, and cytosolic accumulation of collagen polypeptides, indicating loss of coordinated translation. |
ER membrane fractionation, siRNA knockdown, nonmuscle myosin depolymerization, Western blot, microscopy |
PloS one |
High |
25271881
|
| 2013 |
FKBP3 (FKBP25) interacts with LARP6 and co-immunoprecipitates collagen mRNAs. FK506 (tacrolimus) weakens the FKBP3–LARP6 interaction, reducing pull-down of collagen mRNAs by FKBP3 and inhibiting translation of collagen α1(I) polypeptide without affecting collagen mRNA levels. |
Co-IP, Western blot, FK506 pharmacological treatment, in vitro collagen synthesis assay |
PloS one |
Medium |
23755290
|
| 2016 |
LARP6 is phosphorylated at 8 serines in lung fibroblasts; phosphorylation follows a hierarchical order with S451 as a prerequisite for other phosphorylations. PI3K/Akt pathway (specifically Akt kinase) phosphorylates S451. S451A mutant has a dominant-negative effect on collagen biosynthesis, drastically reducing collagen secretion and inducing hypermodification of collagen α2(I) polypeptides. |
Mass spectrometry phosphosite mapping, PI3K/Akt inhibition, site-directed mutagenesis (S451A dominant negative), collagen secretion assay |
Scientific reports |
High |
26932461
|
| 2017 |
mTORC1 phosphorylates LARP6 on S348 and S409. The S348A/S409A mutant acts as a dominant-negative in collagen biosynthesis, retarding secretion and causing excessive posttranslational modifications. S348A/S409A weakly interacts with accessory protein STRAP (needed for coordinated translation); mTORC1 inhibitor rapamycin or raptor knockdown attenuates this interaction. Loss of S348/S409 phosphorylation also sequesters LARP6 at the ER membrane. |
Site-directed mutagenesis, rapamycin treatment, raptor siRNA knockdown, Co-IP (LARP6–STRAP), collagen secretion assay, ER fractionation |
Scientific reports |
High |
28112218
|
| 2021 |
The La domain of LARP6 is necessary and sufficient for sequence-specific recognition of the 5'SL RNA. A three-amino-acid RNK motif in the flexible loop connecting the second α-helix to the β-sheet of the La domain is critical for binding; mutation of any of these three residues abolishes binding. The RRM domain stabilizes the La domain–5'SL complex but does not make extensive contacts with 5'SL. The major UV crosslinking site of LARP6 to 5'SL RNA maps to this RNK motif. The RNK motif is absent in other LARPs, which cannot bind 5'SL. |
Mutagenesis, gel mobility shift, UV crosslinking, domain deletion analysis |
Journal of molecular biology |
High |
34896113
|
| 2021 |
ER-anchored CRTH2 (trafficked to ER membrane in a caveolin-1-dependent manner) binds the collagen mRNA recognition motif of LARP6, promoting degradation of collagen mRNA in fibroblasts. CRTH2 deficiency increases collagen biosynthesis, and this effect is rescued by LARP6 depletion, placing CRTH2 upstream of LARP6 in collagen mRNA regulation. |
Co-IP (CRTH2–LARP6 interaction), caveolin-1 KO (trafficking), genetic epistasis (CRTH2 KO + LARP6 KD rescue), collagen mRNA stability assay |
The EMBO journal |
High |
34223653
|
| 2023 |
LARP6 binds ZNF267 mRNA and regulates its stability and translation. This leads to inhibition of SGMS2 (a downstream target of ZNF267), causing ceramide/sphingomyelin imbalance in colorectal cancer cells. LARP6 also enhances autophagy activity in CRC cells, at least partially through inhibition of SGMS2-mediated sphingomyelin synthesis. |
RIP-seq, RIP-qPCR, LARP6 overexpression/knockdown, Western blot, autophagy assays |
Journal of experimental & clinical cancer research |
Medium |
36691044
|
| 2024 |
In Xenopus multiciliated cells, LARP6 and DNAAF6 colocalize in biomolecular condensates (dynein axonemal particles). LARP6 binds tubulin alpha 1c-like mRNA encoding α-tubulin (a major component of ciliary axoneme). DNAAF6 is required for high α-tubulin protein expression near the apical side during ciliogenesis, and a DNAAF6 mutant that cannot bind LARP6 fails to restore apical α-tubulin expression, demonstrating that the LARP6–DNAAF6 interaction is required for ciliogenesis. |
Co-IP (LARP6–DNAAF6), live imaging/colocalization in condensates, Xenopus morphant/rescue experiments, mutagenesis of DNAAF6 binding interface |
The Journal of biological chemistry |
Medium |
38762183
|
| 2026 |
eCLIP and ribosome profiling in human hepatic stellate cells showed that LARP6 interacts with mature mRNAs of >300 genes, binding RNA structural elements within COL1A1, COL1A2, and COL3A1 to regulate mRNA expression and translation. IP-mass spectrometry identified LARP6 protein-protein interactions with mRNA translation components and the actin cytoskeleton. JUNB transcription factor upregulates LARP6 expression in activated HSCs. |
eCLIP, ribosome profiling, IP-mass spectrometry, snRNA-seq, ATAC-seq, siRNA knockdown |
The Journal of clinical investigation |
High |
41746718
|
| 2026 |
The N-terminal intrinsically disordered region (IDR) of LARP6 restricts the conformational flexibility of the adjacent La-module and forms auxiliary contacts with RNA, thereby narrowing LARP6 RNA-binding selectivity. Deletion of the N-terminal IDR broadens LARP6 RNA footprints (detected by iCLIP). IDR-mediated RNA-binding selectivity is critical for LARP6-driven cancer cell viability and invasion. The La-module (not IDRs) is essential for RNA binding per se. |
Mass spectrometry-based RNA interaction mapping in living cells, iCLIP, mutagenesis/deletion analysis, cancer cell viability and invasion assays |
Nature communications |
High |
41714637
|
| 2009 |
Acheron/LARP6 acts upstream of the muscle-specific transcription factor MyoD in C2C12 myoblasts. Forced expression of ectopic Acheron results in larger myotubes and reserve cell death; dominant-negative or antisense Acheron blocks myotube formation. In zebrafish, antisense morpholino reduction of Acheron leads to muscle fiber loss, while ectopic Acheron enhances muscle fiber formation. |
C2C12 myoblast differentiation assay, ectopic expression, dominant-negative expression, antisense knockdown, zebrafish morpholino |
Mechanisms of development |
Medium |
19481601
|
| 2009 |
Acheron/LARP6 controls expression of the laminin receptor integrin α7β1 during myoblast differentiation; loss of Acheron (via antisense or deletion mutant) blocks laminin receptor expression and reduces substrate adhesion and migration on laminin but not fibronectin, linking Acheron to integrin-mediated extracellular matrix interactions during myogenesis. |
Ectopic expression, antisense/dominant-negative deletion mutant, integrin expression (Western blot/flow cytometry), adhesion and migration assays |
American journal of physiology. Cell physiology |
Medium |
19889961
|
| 2011 |
In human breast cancer MDA-MB-231 cells, Acheron/LARP6 enhances cell proliferation, lamellipodia formation, invasive activity, and drives elevated expression of MMP-9 and VEGF. Nuclear localization is required: AchnNLS (lacking NLS) did not enhance these activities, while AchnNES (lacking NES, thus retained in nucleus) did, indicating that nuclear localization is necessary for Acheron's pro-tumorigenic activity. |
Stable expression of GFP-tagged Acheron variants (WT, ΔNLS, ΔNES), proliferation assay, invasion assay, in vivo xenograft (SCID/Beige mice), Western blot for MMP-9/VEGF |
International journal of cancer |
Medium |
21387291
|
| 2020 |
In Manduca sexta ISMs, Acheron/LARP6 functions as a survival protein protecting muscles until eclosion; at eclosion it becomes phosphorylated and degraded in response to Eclosion Hormone (EH). Acheron binds a novel BH3-only protein BBH1 (BAD/BNIP3 homology 1); BBH1 accumulates when muscles commit to die and is presumably liberated upon Acheron degradation, correlated with cytochrome c release and cell death. RNAi in Drosophila confirmed loss of Acheron causes precocious muscle death. |
Co-IP (Acheron–BBH1), phosphorylation assay (EH-stimulated), RNAi in Drosophila, cytochrome c release assay |
Frontiers in cell and developmental biology |
Medium |
32850788
|
| 2025 |
De novo solution NMR structure of the La domain of human LARP6 in complex with 5'SL RNA reveals a non-canonical binding interface integrating electrostatic and hydrophobic contacts with shape complementarity. Chemical shift perturbation, solvent paramagnetic relaxation enhancement, intermolecular NOEs, and targeted mutagenesis converge on this interface. The La domain alone discriminates 5'SL from homopolymeric or purely helical hairpin RNAs with low-nanomolar affinity, overturning the view that the RRM is required for recognition. |
Solution NMR structure determination, chemical shift perturbation, paramagnetic relaxation enhancement, intermolecular NOEs, mutagenesis, RNA binding affinity measurements |
bioRxivpreprint |
High |
bio_10.1101_2025.05.22.652967
|
| 2025 |
The La domain of LARP6 is stabilized >50-fold when in complex with its cognate 5'SL RNA compared to the unbound (aggregation-prone) state. C-terminal truncations greatly impair protein stability while N-terminal truncations have little effect on aggregation or RNA binding. |
Recombinant protein expression, limited proteolysis, stability assays, RNA binding assays |
ACS omega |
Medium |
40191362
|
| 2025 |
LARP6 regulates alternative splicing of >1000 events in MDA-MB-231 TNBC cells and tends to bind the CGACGAG motif. iRIP-seq identified 16 genes where LARP6 directly binds and regulates alternative splicing, with enrichment in DNA repair and cell cycle pathways. |
RNA-seq, iRIP-seq, RT-qPCR, RIP-qPCR |
Scientific reports |
Medium |
40050364
|