6nzd

Structural highlights

Function

LTOR1_HUMAN As part of the Ragulator complex it is involved in amino acid sensing and activation of mTORC1, a signaling complex promoting cell growth in response to growth factors, energy levels, and amino acids. Activated by amino acids through a mechanism involving the lysosomal V-ATPase, the Ragulator functions as a guanine nucleotide exchange factor activating the small GTPases Rag. Activated Ragulator and Rag GTPases function as a scaffold recruiting mTORC1 to lysosomes where it is in turn activated. LAMTOR1 is directly responsible for anchoring the Ragulator complex to membranes. Also required for late endosomes/lysosomes biogenesis it may regulate both the recycling of receptors through endosomes and the MAPK signaling pathway through recruitment of some of its components to late endosomes. May be involved in cholesterol homeostasis regulating LDL uptake and cholesterol release from late endosomes/lysosomes. May also play a role in RHOA activation.^{[1] [2] [3] [4]}

See Also

• GTP-binding protein 3D structures
• Ragulator complex 3D structures

References

1. ↑ Hoshino D, Tomari T, Nagano M, Koshikawa N, Seiki M. A novel protein associated with membrane-type 1 matrix metalloproteinase binds p27(kip1) and regulates RhoA activation, actin remodeling, and matrigel invasion. J Biol Chem. 2009 Oct 2;284(40):27315-26. doi: 10.1074/jbc.M109.041400. Epub 2009, Aug 4. PMID:19654316 doi:http://dx.doi.org/10.1074/jbc.M109.041400
2. ↑ Sancak Y, Bar-Peled L, Zoncu R, Markhard AL, Nada S, Sabatini DM. Ragulator-Rag complex targets mTORC1 to the lysosomal surface and is necessary for its activation by amino acids. Cell. 2010 Apr 16;141(2):290-303. doi: 10.1016/j.cell.2010.02.024. Epub 2010 Apr , 8. PMID:20381137 doi:10.1016/j.cell.2010.02.024
3. ↑ Guillaumot P, Luquain C, Malek M, Huber AL, Brugiere S, Garin J, Grunwald D, Regnier D, Petrilli V, Lefai E, Manie SN. Pdro, a protein associated with late endosomes and lysosomes and implicated in cellular cholesterol homeostasis. PLoS One. 2010 Jun 8;5(6):e10977. doi: 10.1371/journal.pone.0010977. PMID:20544018 doi:http://dx.doi.org/10.1371/journal.pone.0010977
4. ↑ Bar-Peled L, Schweitzer LD, Zoncu R, Sabatini DM. Ragulator is a GEF for the rag GTPases that signal amino acid levels to mTORC1. Cell. 2012 Sep 14;150(6):1196-208. doi: 10.1016/j.cell.2012.07.032. PMID:22980980 doi:10.1016/j.cell.2012.07.032
5. ↑ Lawrence RE, Fromm SA, Fu Y, Yokom AL, Kim DJ, Thelen AM, Young LN, Lim CY, Samelson AJ, Hurley JH, Zoncu R. Structural mechanism of a Rag GTPase activation checkpoint by the lysosomal folliculin complex. Science. 2019 Oct 31. pii: science.aax0364. doi: 10.1126/science.aax0364. PMID:31672913 doi:http://dx.doi.org/10.1126/science.aax0364