6nzd
From Proteopedia
| Line 21: | Line 21: | ||
</div> | </div> | ||
<div class="pdbe-citations 6nzd" style="background-color:#fffaf0;"></div> | <div class="pdbe-citations 6nzd" style="background-color:#fffaf0;"></div> | ||
| + | |||
| + | ==See Also== | ||
| + | *[[Ragulator complex|Ragulator complex]] | ||
== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 11:50, 18 December 2019
Cryo-EM Structure of the Lysosomal Folliculin Complex (FLCN-FNIP2-RagA-RagC-Ragulator)
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. [FLCN_HUMAN] Familial spontaneous pneumothorax;Birt-Hogg-Dube syndrome. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. The gene represented in this entry may be involved in disease pathogenesis. 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] [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.[5] [6] [RRAGC_HUMAN] 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.[7] [FNIP2_HUMAN] Acts as a co-chaperone of HSP90AA1. Inhibits the ATPase activity of HSP90AA1 leading to reduction in its chaperone activity. Facilitates the binding of client protein FLCN to HSP90AA1 (PubMed:27353360). May play a role in the signal transduction pathway of apoptosis induced by O6-methylguanine-mispaired lesions (By similarity). May be involved in energy and/or nutrient sensing through the AMPK and mTOR signaling pathways (PubMed:18403135). May regulate phosphorylation of RPS6KB1 (PubMed:18663353).[UniProtKB:Q80TD3][8] [9] [10] [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.[11] [12] [FLCN_HUMAN] May play a role in the pathogenesis of an uncommon form of kidney cancer through its association with an inherited disorder of the hair follicle (fibrofolliculomas). May be a tumor suppressor. May be involved in colorectal tumorigenesis. May be involved in energy and/or nutrient sensing through the AMPK and mTOR signaling pathways. May regulate phosphorylation of RPS6KB1.[13] [14] [15] [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.[16] [17] [18] [19] [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.[20] Publication Abstract from PubMedThe tumor suppressor folliculin (FLCN) enables nutrient-dependent activation of the mechanistic target of rapamycin complex 1 (mTORC1) protein kinase via its guanosine triphosphatase (GTPase) Activating Protein (GAP) activity toward the GTPase RagC. Concomitant with mTORC1 inactivation by starvation, FLCN relocalizes from the cytosol to lysosomes. To determine the lysosomal function of FLCN, we reconstituted the lysosomal FLCN complex (LFC) containing FLCN, its partner FLCN-interacting protein 2 (FNIP2), the RagA(GDP):RagC(GTP) GTPases as they exist in the starved state with their lysosomal anchor Ragulator complex, and determined its cryo-EM structure to 3.6 A. The RagC-GAP activity of FLCN was inhibited within LFC, due to displacement of a catalytically required Arginine in FLCN from the RagC nucleotide. Disassembly of the LFC and release of the RagC-GAP activity of FLCN enabled mTORC1-dependent regulation of the master regulator of lysosomal biogenesis, transcription factor E3, implicating the LFC as a checkpoint in mTORC1 signaling. Structural mechanism of a Rag GTPase activation checkpoint by the lysosomal folliculin complex.,Lawrence RE, Fromm SA, Fu Y, Yokom AL, Kim DJ, Thelen AM, Young LN, Lim CY, Samelson AJ, Hurley JH, Zoncu R Science. 2019 Oct 31. pii: science.aax0364. doi: 10.1126/science.aax0364. PMID:31672913[21] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||||
