| 2015 |
SLC38A9 is a lysosomal transmembrane protein that physically interacts with the Rag GTPases and Ragulator complex in an amino acid-sensitive fashion, transports arginine with a high Km, and its loss represses mTORC1 activation by amino acids (particularly arginine); overexpression of SLC38A9 or just its Ragulator-binding domain makes mTORC1 signaling insensitive to amino acid starvation but not to Rag activity, placing SLC38A9 upstream of the Rag GTPases. |
Co-immunoprecipitation, amino acid transport assays, loss-of-function (knockdown/knockout) with mTORC1 activity readout, domain overexpression epistasis |
Science |
High |
25567906
|
| 2015 |
SLC38A9 is an integral component of the Ragulator–RAG GTPase machinery at the lysosomal membrane; gain-of-function renders cells resistant to amino acid withdrawal and loss impairs amino-acid-induced mTORC1 activation, established by extensive functional proteomics and functional validation. |
Functional proteomics (AP-MS), gain/loss-of-function with mTORC1 activity readout, lysosomal fractionation |
Nature |
High |
25561175
|
| 2015 |
SLC38A9 is an 11-pass lysosomal transmembrane protein that associates with Rag GTPases in an amino acid-sensitive and nucleotide binding state-dependent manner; SLC38A9 depletion inhibits mTORC1 activity in the presence of amino acids; overexpression causes RHEB-dependent hyperactivation of mTORC1; during amino acid starvation, mTOR is retained at the lysosome upon SLC38A9 depletion but fails to be activated. |
Co-immunoprecipitation, siRNA knockdown/overexpression with mTORC1 readout, lysosomal localization by fluorescence microscopy |
Molecular and Cellular Biology |
High |
25963655
|
| 2017 |
SLC38A9 mediates the transport of many essential amino acids (including leucine) out of lysosomes in an arginine-regulated fashion; it is required for leucine generated via lysosomal proteolysis to exit lysosomes and activate mTORC1; pancreatic cancer cells using macropinocytosed protein as a nutrient source require SLC38A9 to form tumors. |
Isotope tracing/transport assays, lysosome immunopurification (Lyso-IP), SLC38A9 knockout cells, tumor formation assays |
Cell |
High |
29053970
|
| 2017 |
Lysosomal cholesterol activates mTORC1 through SLC38A9 via conserved cholesterol-responsive motifs; SLC38A9 enables mTORC1 activation by cholesterol independently from its arginine-sensing function; NPC1 binds to SLC38A9 and inhibits mTORC1 signaling through its sterol transport function. |
Co-immunoprecipitation (SLC38A9–NPC1 interaction), cholesterol depletion/repletion experiments, mutagenesis of cholesterol-responsive motifs, loss-of-function with mTORC1 readout |
Science |
High |
28336668
|
| 2018 |
Ragulator and SLC38A9 are each guanine nucleotide exchange factors (GEFs) that collectively push Rag GTPases toward the active state: Ragulator triggers GTP release from RagC (resolving the locked inactive state), while upon arginine binding, SLC38A9 converts RagA from GDP- to GTP-loaded state, activating the Rag GTPase heterodimer. |
GEF activity assay (nucleotide exchange biochemistry), reconstituted Rag GTPase assays, arginine-binding experiments |
Proceedings of the National Academy of Sciences |
High |
30181260
|
| 2018 |
Crystal structure of zebrafish SLC38A9 in complex with arginine captured in the cytosol-open state; the bound arginine is locked in a transitional state stabilized by TM1 anchored at the groove between TM5 and TM7 via the conserved WNTMM motif; mutations in the WNTMM motif abolish arginine transport. |
X-ray crystallography, site-directed mutagenesis, arginine transport assay |
Nature Structural & Molecular Biology |
High |
29872228
|
| 2019 |
Human SLC38A9 reconstituted in liposomes transports both glutamine and arginine with cooperative kinetics; a Na+ binding site at T453 was identified by mutagenesis; cholesterol stimulates glutamine and arginine transport; the N-terminal tail is not required for intrinsic transport function; SLC38A9 is competent for glutamine efflux but arginine efflux is negligible; arginine acts as a modulator stimulating glutamine efflux; glutamine and arginine likely bind to different sites. |
Protein reconstitution in liposomes, transport assays, site-directed mutagenesis, bioinformatics-guided mutagenesis, N-terminal deletion mutant |
Biochimica et Biophysica Acta – Biomembranes |
High |
31295473
|
| 2020 |
The cytoplasmic tail of SLC38A9 destabilizes the lysosomal folliculin complex (LFC, consisting of inactive Rag dimer, Ragulator, and FLCN:FNIP2 GAP), triggering GAP activity of FLCN:FNIP2 toward RagC; cryo-EM structures of Rags–Ragulator–SLC38A9 cytoplasmic tail in pre- and post-GTP hydrolysis states of RagC explain mechanistically how SLC38A9 promotes Rag dimer activation. |
Cryo-EM structure determination, in vitro GAP activity assay, biochemical reconstitution of LFC disassembly |
Nature Structural & Molecular Biology |
High |
32868926
|
| 2021 |
SLC38A9 interacts with SLC36A1 in C2C12 cells; they enhance each other's expression levels and lysosomal surface localization; SLC38A9 interacting proteins in C2C12 cells participate in amino acid sensing, mTORC1 signaling, and protein synthesis pathways. |
Co-immunoprecipitation, immunofluorescence co-localization, proteomics of SLC38A9 interactors |
Biomolecules |
Medium |
34572527
|
| 2021 |
ATF4 binds to two amino acid response elements (AAREs) found in the SLC38A9 promoter/first intron region and regulates SLC38A9 mRNA expression in porcine skeletal muscle cells; the AARE in the first intron is located in the core promoter region of SLC38A9. |
Promoter analysis, chromatin immunoprecipitation / AARE binding assay, siRNA knockdown of ATF4, RT-qPCR |
Biochemical and Biophysical Research Communications |
Medium |
34246831
|
| 2024 |
SLC38A9 interacts with the SARS-CoV-2 S1 protein multibasic motif in the endolysosome; SLC38A9 knockdown prevents S1-induced endolysosome de-acidification and blocks S protein-mediated entry of pseudo-SARS-CoV-2 in multiple cell lines. |
Co-immunoprecipitation (SLC38A9–S1 interaction), siRNA knockdown, pseudo-virus entry assay, endolysosomal pH measurement |
iScience |
Medium |
39071889
|
| 2025 |
HIV-1 Tat interacts with SLC38A9 via its arginine-rich basic domain in the endolysosome; this interaction leads to endolysosome dysfunction, enhanced HIV-1 LTR transactivation, and cellular senescence in human astrocytes. |
Co-immunoprecipitation, domain mapping (arginine-rich domain), endolysosomal function assays, senescence assays |
Life Science Alliance |
Medium |
40324823
|
| 2023 |
RBM25 binds to and regulates alternative splicing of Slc38a9 in H9c2 cardiomyocyte cells, as established by iRIP-seq binding identification and RT-qPCR validation. |
iRIP-seq, RNA-seq, RT-qPCR validation |
PeerJ |
Low |
37953772
|
| 2024 |
SLC38A9 promotes outward lysosome transport along a SLC38A9-BORC-kinesin 1/3 axis in response to amino acids; this lysosome dispersal function is distinct from its mTORC1-activating arginine-sensing function; aromatic amino acids (e.g., phenylalanine) promote lysosome peripheral redistribution via SLC38A9, and combining lysosome-dispersing amino acids with arginine synergistically enhances mTOR activation in a kinesin 1/3-dependent manner. |
High-content imaging of lysosome positioning, kinesin 1/3 KO cells, SLC38A9 perturbation, amino acid titrations with mTOR readout |
bioRxivpreprint |
Low |
bio_10.1101_2024.10.12.618047
|
| 2025 |
Arginine uptake by SLC38A9 is pH-dependent; His544 serves as the pH sensor, with its protonation/deprotonation influencing transport; mutating His544 abolishes pH dependence of arginine uptake without impairing overall transport activity, indicating His544 is not directly involved in substrate binding; two SLC38A9 structures at high and low pH reveal the structural basis of pH-induced activation. |
Transport assays at different pH, site-directed mutagenesis of His544, cryo-EM/structural comparison at two pH values |
FEBS Letters / bioRxiv |
Medium |
41279478 42070976
|