| 1994 |
SRP9 and SRP14 form a heterodimer that binds SRP RNA and is required for elongation arrest activity; fusion single-chain polypeptides containing both sequences retain RNA binding and elongation arrest activity, demonstrating that the normal N- and C-termini are dispensable for folding, RNA-binding, and biological activities. |
In vitro reconstitution with fusion proteins, SRP RNA binding assay, elongation arrest and translocation cell-free assays |
Nucleic acids research |
High |
7518078
|
| 1995 |
Human SRP9, together with SRP14, forms the Alu RNA-binding protein (RBP) activity; the SRP9/14 heterodimer binds the Alu region of 7SL RNA, scAlu RNA, and scB1 RNA with Kd values of ~203 pM, ~318 pM, and ~1.8 nM respectively; the primate-specific C-terminal tail of SRP14 does not appreciably affect scAlu RNA binding. |
Purification of SRP9/14 from HeLa cells, quantitative equilibrium binding assays (Kd determination) |
The Journal of biological chemistry |
High |
7730321
|
| 1995 |
SRP9/14 is present in >20-fold excess over SRP in primate cells; the excess is predominantly cytoplasmic and largely free of small RNAs, but a significant fraction of small cytoplasmic Alu RNA is complexed with SRP9/14 in an 8.5S particle in vivo. |
Antibody characterization, subcellular fractionation, immunoprecipitation, sedimentation analysis |
Molecular biology of the cell |
Medium |
7542942
|
| 1996 |
SRP9 was crystallized and X-ray diffraction data collected to 2.3 Å resolution, establishing the feasibility of structural analysis of the mouse SRP9 protein. |
Protein crystallography (hanging drop vapor diffusion, X-ray diffraction) |
FEBS letters |
Low |
8617357
|
| 1996 |
SRP9 immunoprecipitates both scAlu RNA and dimeric Alu RNAs in vivo; adenovirus infection increases dimeric Alu RNP levels without affecting SRP9, SRP14, SRP54, or 7SL RNA levels, showing that induced Alu transcripts are assembled into SRP9/14-containing RNPs. |
Immunoprecipitation with anti-SRP9 antiserum from HeLa cells, Northern blotting |
Nucleic acids research |
Medium |
8932367
|
| 1997 |
Crystal structure of the mouse SRP9/14 heterodimer resolved at 2.5 Å reveals that SRP9 and SRP14 are structurally homologous, each containing an alpha-beta-beta-beta-alpha fold (designated the Alu binding module); the heterodimer has pseudo 2-fold symmetry, is saddle-shaped with a curved six-stranded amphipathic beta-sheet, and presents a positively charged concave surface proposed to interact with RNA. |
X-ray crystallography at 2.5 Å resolution |
The EMBO journal |
High |
9233785
|
| 1997 |
Human SRP9/14 binds with higher affinity than mouse SRP9/14 to all Alu-like RNAs tested (including BC200 RNA), and this difference is not explained by the additional C-terminal domain of anthropoid SRP14; relative dissociation constants are inversely proportional to evolutionary distance between the Alu RNA species and 7SL RNA. |
In vitro RNA-binding assays comparing human and mouse SRP9/14 with multiple Alu-like RNAs |
Nucleic acids research |
Medium |
9016560
|
| 1997 |
A minimal 86-nucleotide Alu RNA folding domain (SA86) specifically binds SRP9/14 (as a fusion SRPphi14-9); smaller RNAs fail to compete, and circularly permuted variants require a ≥4-nt linker to compete, indicating that Alu RNA identity is determined by a characteristic tertiary structure. |
In vitro equilibrium competition binding assay with ribozyme-generated RNA variants |
RNA (New York, N.Y.) |
High |
9409618
|
| 1997 |
G24 of SRP RNA is critical for high-affinity binding to SRP9/14; G24C mutation reduces SRP9/14 binding ≥50-fold, G24A ~2-fold, G24U ~5-fold; despite impaired binding, reconstituted SRPs with mutant RNAs retain translation arrest activity, indicating G24 promotes arrest indirectly by mediating SRP9/14 binding affinity rather than direct interaction with the translational machinery. |
Site-directed mutagenesis of SRP RNA, in vitro SRP9/14 binding assays, cell-free translation arrest reconstitution |
Nucleic acids research |
High |
9092618
|
| 1997 |
Mutations accompanying Alu RNA evolution in the right monomer destabilized a conserved structural motif and decreased its affinity for SRP9/14; the Alu left monomer maintained structural integrity and high SRP9/14 affinity; loss of right monomer SRP9/14 affinity correlates with increased scAlu RNA production from Alu elements in vivo and with decreased Alu amplification rates. |
In vitro binding assays with evolutionary Alu RNA variants, structural analysis, in vivo correlations |
Molecular and cellular biology |
Medium |
9032241
|
| 1998 |
SRP9 protein is a component of the neural BC200 RNP in primate brain in vivo; anti-SRP9 antibody immunoprecipitates BC200 RNA, indicating SRP9/14 binds the Alu-like 5' domain of BC200 RNA in neurons. |
Immunoprecipitation with anti-SRP9 antibody from primate brain, RNA analysis |
Neuroscience letters |
Medium |
9605471
|
| 2010 |
Two patches of positively charged residues in SRP9/14 are essential for elongation arrest activity: a basic pentapeptide KRDKK in SRP14 (replaceable by four lysines) and three lysines in the solvent-accessible alpha2 helix of SRP9; all essential residues localize to one face of SRP9/14, forming a positively charged platform likely mediating electrostatic interactions with ribosomal RNA; the internal loop of SRP14 is dispensable. |
Site-directed mutagenesis, cell-free translation/translocation assays, mammalian cell-based assays |
RNA (New York, N.Y.) |
High |
20348448
|
| 2014 |
SRP9/14 (but not SRP) localizes to stress granules (SGs) following arsenite or hippuristanol treatment; this localization depends on its ability to bind directly to 40S ribosomal subunits; depletion of SRP9/14 decreases SG size and number of SG-positive cells; binding of SRP9/14 to 40S and to Alu RNA is mutually exclusive, and increasing cytoplasmic Alu RNA promotes SG disassembly by competitively disengaging SRP9/14 from 40S. |
Immunofluorescence localization, siRNA depletion, 40S binding assays, Alu RNA overexpression and binding-defective mutant expression in human cells |
Nucleic acids research |
High |
25200073
|
| 2015 |
Alu RNPs inhibit both cap-dependent and IRES-mediated translation initiation; inhibition involves direct binding of SRP9/14 to 40S ribosomal subunits and requires Alu RNA as an assembly factor but not its continuous association with 40S; SRP9/14 bound to 40S prevents 48S complex formation by blocking mRNA recruitment to 40S subunits; in cells, Alu RNA overexpression decreases translation of reporter mRNAs in an SRP9/14 binding-dependent manner. |
Cell-free translation assays, 40S binding assays, 48S complex formation assays, reporter translation assays in cells with Alu RNA mutants |
Nucleic acids research |
High |
25697503
|
| 2014 |
In vivo knockdown of brain Srp9 reduces febrile seizure susceptibility in mice and reduces hippocampal AMPA and NMDA currents; downregulation of neuronal Srp9 reduces surface expression of AMPA receptor subunit GluA1, indicating SRP9 conveys its effects through ER-dependent synthesis and trafficking of membrane proteins including glutamate receptors. |
In vivo Srp9 knockdown, electrophysiology (AMPA/NMDA currents), surface expression assays for GluA1 |
Annals of clinical and translational neurology |
Medium |
25590037
|
| 2023 |
SRP9/14 has a distinct nuclear localization (shown by immunofluorescent imaging and subcellular fractionation); nuclear SRP9/14 transcriptionally regulates 7SL RNA and BC200 RNA expression, as demonstrated by changes in steady-state levels and transcriptional activity under SRP9/14 knockdown conditions. |
Immunofluorescence, subcellular fractionation, siRNA knockdown, transcription rate measurements in MCF-7 cells |
RNA (New York, N.Y.) |
Medium |
37156570
|
| 2025 |
The Alu domain of SRP RNA is sufficient to target SRP RNAs to lysosomes for degradation, and this targeting depends on the SRP9 and SRP14 proteins. |
Lysosomal RNA profiling, genetic perturbation of SRP9/SRP14 in cells |
bioRxivpreprint |
Low |
|
| 2024 |
A 46-nucleotide domain at the 5' end of Alu RNA is necessary for retrotransposition; this domain associates with SRP9/14 in HeLa cell extracts and promotes a single round of retrotransposition, consistent with a model in which SRP9/14 binding mediates ribosomal association required for LINE-1 ORF2p hijacking. |
HeLa cell retrotransposition assays, deletion mutagenesis of Alu RNA, immunoprecipitation of SRP9/14 from cell extracts |
bioRxivpreprint |
Low |
|
| 2025 |
The 5' pseudoknot U-turn motif in Alu RNA (critical guanosine) is required for SRP9/14 association; a short human Alu RNA (EB120) that lacks the canonical U-turn nucleotide triad also lacks association with SRP9/14 in cellular context, demonstrating that the pseudoknot fold is required for SRP9/14 binding. |
Co-immunoprecipitation in 18 human cell lines/tissues, site-directed mutagenesis of BC200, SAXS structure prediction of Alu domain variants |
RNA (New York, N.Y.) |
Medium |
40345827
|