F
IPR028209

LAMTOR1/MEH1

InterPro entry
Short nameLAMTOR1/MEH1

Description

LAMTOR1 is a family of eukaryotic proteins that have otherwise been referred to as Lipid raft adaptor protein p18, Late endosomal/lysosomal adaptor and MAPK and MTOR activator 1, and Protein associated with DRMs and endosomes.

LAMTOR1 regulates the mTOR (mammalian target of rapamycin) pathway, a signaling cascade that promotes cell growth in response to growth factors, energy levels, and amino acids. LAMTOR1 is part of the Ragulator complex, recruits the Rag GTPases and the mTORC1 complex to lysosomes, a key step in activation of the TOR signaling cascade by amino acids
[4]
. LAMTOR1 is responsible for anchoring the Ragulator complex to membranes. 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
[2]
. It may be involved in cholesterol homeostasis regulating LDL uptake and cholesterol release from late endosomes/lysosomes. It may also play a role in RHOA activation
[3, 1]
.

This family also includes Saccharomyces cerevisiae MEH1 (Ego1), a component of the EGO complex. The EGO complex and the Rag-Ragulator complex are structurally related
[7]
. The yeast EGO complex consists of Gtr1, Gtr2, Ego1, and Ego3, localises to the endosomal and vacuolar membranes, and plays a crucial role in cell growth and autophagy regulation through amino acid signals that activate TORC1
[6]
. MEH1 (GSE2) is also a component of the GSE complex, which is required for proper sorting of amino acid permease Gap1
[5]
.

References

1.The novel lipid raft adaptor p18 controls endosome dynamics by anchoring the MEK-ERK pathway to late endosomes. Nada S, Hondo A, Kasai A, Koike M, Saito K, Uchiyama Y, Okada M. EMBO J. 28, 477-89, (2009). View articlePMID: 19177150

2.Ragulator-Rag complex targets mTORC1 to the lysosomal surface and is necessary for its activation by amino acids. Sancak Y, Bar-Peled L, Zoncu R, Markhard AL, Nada S, Sabatini DM. Cell 141, 290-303, (2010). View articlePMID: 20381137

3.Pdro, a protein associated with late endosomes and lysosomes and implicated in cellular cholesterol homeostasis. Guillaumot P, Luquain C, Malek M, Huber AL, Brugiere S, Garin J, Grunwald D, Regnier D, Petrilli V, Lefai E, Manie SN. PLoS ONE 5, e10977, (2010). View articlePMID: 20544018

4.A novel protein associated with membrane-type 1 matrix metalloproteinase binds p27(kip1) and regulates RhoA activation, actin remodeling, and matrigel invasion. Hoshino D, Tomari T, Nagano M, Koshikawa N, Seiki M. J. Biol. Chem. 284, 27315-26, (2009). View articlePMID: 19654316

5.A conserved GTPase-containing complex is required for intracellular sorting of the general amino-acid permease in yeast. Gao M, Kaiser CA. Nat. Cell Biol. 8, 657-67, (2006). View articlePMID: 16732272

6.The TOR and EGO protein complexes orchestrate microautophagy in yeast. Dubouloz F, Deloche O, Wanke V, Cameroni E, De Virgilio C. Mol. Cell 19, 15-26, (2005). View articlePMID: 15989961

7.Leucyl-tRNA synthetase controls TORC1 via the EGO complex. Bonfils G, Jaquenoud M, Bontron S, Ostrowicz C, Ungermann C, De Virgilio C. Mol. Cell 46, 105-10, (2012). View articlePMID: 22424774

GO terms

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