| Structural highlights
Disease
[LTOR2_HUMAN] Primary immunodeficiency syndrome due to p14 deficiency. The disease is caused by mutations affecting the gene represented in this entry.
Function
[RRAGA_HUMAN] Guanine nucleotide-binding protein that plays a crucial role in the cellular response to amino acid availability through regulation of the mTORC1 signaling cascade. Forms heterodimeric Rag complexes with RRAGC or RRAGD and cycles between an inactive GDP-bound and an active GTP-bound form. In its active form participates in the relocalization of mTORC1 to the lysosomes and its subsequent activation by the GTPase RHEB. Involved in the RCC1/Ran-GTPase pathway. May play a direct role in a TNF-alpha signaling pathway leading to induction of cell death. May alternatively act as a cellular target for adenovirus E3-14.7K, an inhibitor of TNF-alpha functions, thereby affecting cell death.[1] [2] [3] [4] [LTOR4_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.[5] [LTOR3_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. Adapter protein that enhances the efficiency of the MAP kinase cascade facilitating the activation of MAPK2.[6] [7] [LTOR5_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. When complexed to BIRC5, interferes with apoptosome assembly, preventing recruitment of pro-caspase-9 to oligomerized APAF1, thereby selectively suppressing apoptosis initiated via the mitochondrial/cytochrome c pathway. Down-regulates hepatitis B virus (HBV) replication.[8] [9] [RRAGC_MOUSE] Guanine nucleotide-binding protein forming heterodimeric Rag complexes required for the amino acid-induced relocalization of mTORC1 to the lysosomes and its subsequent activation by the GTPase RHEB. This is a crucial step in the activation of the TOR signaling cascade by amino acids (By similarity). [LTOR2_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. Adapter protein that enhances the efficiency of the MAP kinase cascade facilitating the activation of MAPK2.[10] [11] [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.[12] [13] [14] [15]
Publication Abstract from PubMed
The mechanistic target of rapamycin complex 1 (mTORC1) plays a central role in regulating cell growth and metabolism by responding to cellular nutrient conditions. The activity of mTORC1 is controlled by Rag GTPases, which are anchored to lysosomes via Ragulator, a pentameric protein complex consisting of membrane-anchored p18/LAMTOR1 and two roadblock heterodimers. Here we report the crystal structure of Ragulator in complex with the roadblock domains of RagA-C, which helps to elucidate the molecular basis for the regulation of Rag GTPases. In the structure, p18 wraps around the three pairs of roadblock heterodimers to tandemly assemble them onto lysosomes. Cellular and in vitro analyses further demonstrate that p18 is required for Ragulator-Rag GTPase assembly and amino acid-dependent activation of mTORC1. These results establish p18 as a critical organizing scaffold for the Ragulator-Rag GTPase complex, which may provide a platform for nutrient sensing on lysosomes.
Structural basis for the assembly of the Ragulator-Rag GTPase complex.,Yonehara R, Nada S, Nakai T, Nakai M, Kitamura A, Ogawa A, Nakatsumi H, Nakayama KI, Li S, Standley DM, Yamashita E, Nakagawa A, Okada M Nat Commun. 2017 Nov 20;8(1):1625. doi: 10.1038/s41467-017-01762-3. PMID:29158492[16]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ 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
- ↑ Deng L, Jiang C, Chen L, Jin J, Wei J, Zhao L, Chen M, Pan W, Xu Y, Chu H, Wang X, Ge X, Li D, Liao L, Liu M, Li L, Wang P. The ubiquitination of rag A GTPase by RNF152 negatively regulates mTORC1 activation. Mol Cell. 2015 Jun 4;58(5):804-18. doi: 10.1016/j.molcel.2015.03.033. Epub 2015, Apr 30. PMID:25936802 doi:http://dx.doi.org/10.1016/j.molcel.2015.03.033
- ↑ Li Y, Kang J, Horwitz MS. Interaction of an adenovirus 14.7-kilodalton protein inhibitor of tumor necrosis factor alpha cytolysis with a new member of the GTPase superfamily of signal transducers. J Virol. 1997 Feb;71(2):1576-82. PMID:8995684
- ↑ Hirose E, Nakashima N, Sekiguchi T, Nishimoto T. RagA is a functional homologue of S. cerevisiae Gtr1p involved in the Ran/Gsp1-GTPase pathway. J Cell Sci. 1998 Jan;111 ( Pt 1):11-21. PMID:9394008
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ Marusawa H, Matsuzawa S, Welsh K, Zou H, Armstrong R, Tamm I, Reed JC. HBXIP functions as a cofactor of survivin in apoptosis suppression. EMBO J. 2003 Jun 2;22(11):2729-40. PMID:12773388 doi:10.1093/emboj/cdg263
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ Yonehara R, Nada S, Nakai T, Nakai M, Kitamura A, Ogawa A, Nakatsumi H, Nakayama KI, Li S, Standley DM, Yamashita E, Nakagawa A, Okada M. Structural basis for the assembly of the Ragulator-Rag GTPase complex. Nat Commun. 2017 Nov 20;8(1):1625. doi: 10.1038/s41467-017-01762-3. PMID:29158492 doi:http://dx.doi.org/10.1038/s41467-017-01762-3
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