TRG_DiLeu_BaEn_2
Accession: | |
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Functional site class: | Adaptin binding Endosome-Lysosome-Basolateral sorting signals |
Functional site description: | Endocytosis and/or vesicular sorting signals for membrane proteins. Depending on organism, cell type as well as the nature of the adaptin complex bound, they can target either to cell surface or to specific, internal membrane-bound organelles (endosomes, lysosomes, melanosomes, synaptic vesicles, etc.) All these motifs are believed to bind to the sigma subunit of activated adaptin complexes (AP-1, AP-2 and AP-3). These clathrin-associated complexes are ancient and found in most eukaryotes. Dileucine motifs are variable (especially at their negatively charged positions and at the hydrophobic residues) and the various motif subtypes tend to have slightly different functions (Mattera,2011). One should avoid confusing the adaptin sigma-binding classical dileucine motifs discussed here, and the GGA-binding lysosomal targeting motifs (sometimes also called dileucine motifs). |
ELMs with same func. site: | TRG_DiLeu_BaEn_1 TRG_DiLeu_BaEn_2 TRG_DiLeu_BaEn_3 TRG_DiLeu_BaEn_4 TRG_DiLeu_BaLyEn_6 TRG_DiLeu_LyEn_5 |
ELM Description: | This relatively uncommon acidic dileucine-type motif features a phenylalanine at its first hydrophobic position (+5) instead of a leucine (Iverson,2005). Numbering is from the required Glu as +1. Motifs of this subtype are typically involved in basolateral sorting of membrane proteins in polarized epithelial cells (believed to be primarily driven by AP-1 association). Since Phe-containing motifs do not appear to be suitable to act as a lysosomal signal, these variant motifs can also carry a proline before the two hydrophobic residues without the protein becoming lysosomal/late endosomal. Adding an additional negative charge (particularly glutamate) before its canonical glutamate (+1) would however strengthen them to the point where they would act mostly as a vesicular targeting signal (now considered to be a separate motif subtype in ELM) and therefore is disallowed for this functional variant. Unfortunately, no detailed structural information is available on these motifs yet (as of 2021). Phe +5-containing dileucine motifs have not yet been described outside multicellular animals and it is questionable if they exist in fungi or plants. |
Pattern: | [^E]E...F[LIVM] |
Pattern Probability: | 0.0002451 |
Present in taxon: | Metazoa |
Interaction Domain: |
Clat_adaptor_s (PF01217)
Clathrin adaptor complex small chain
(Stochiometry: 1 : 1)
|
Abstract |
Adaptin-binding acidic dileucine motifs and variants thereof occur almost exclusively on the cytosolic side of membrane proteins, mostly integral (transmembrane) proteins. In the latter, they are frequently located near the protein N- or C-termini, with relative proximity (within 10-100aa) to a transmembrane segment. These motifs bind directly to a highly conserved site located on the sigma subunits of adaptin complexes (adaptins AP1-4; Doray,2007; Kelly,2008). They serve to initiate clathrin-mediated endocytosis or protein sorting and can work synergistically with the adaptin mu subunit binding YxxPhi-type motifs (TRG_ENDOCYTIC_2). Sigma subunits of AP complexes differ slightly in their surface charge densities and binding groove geometry, allowing for both generic and selective interactions with protein partners. In multicellular animals, AP1 targets its ligands from the trans-Golgi network to the cell membrane, mainly to the basolateral surface of polarized epithelial cells or somato-dendritic compartment of neurons (Nakatsu,2014). AP2 is chiefly involved in endocytosis of cell surface proteins and their trafficking to early or late endosomes. AP3 targets its ligands to the lysosome, late endosome or melanosome (or less commonly, to the axonal compartment of neurons), while the biological function of AP4 remains mostly unknown. In fungi and plants, dileucine motifs are often responsible for the vacuolar or tonoplast localization of proteins carrying these motifs. Due to the similarity of the adaptin sigma subunits, variant dileucine motifs may have overlapping specificities, being capable of binding multiple adaptins. In many eukaryotes, AP3 appears to be a dominant partner, that drives permanent intracellular localization of ligands it can interact with, regardless of their binding to other adaptins. Unfortunately, the similarity of this motif to the GGA-binding dileucine motifs (that also target certain proteins to the late endosome or lysosome) has been the source of considerable confusion in the past. The name of classical dileucine motifs stems from their preferred hydrophobic amino acids, although it is somewhat of a misnomer. In addition to the idealized ExxPL[LI] sequence, a multitude of relaxed motif variations are reported to exist, many of them still poorly characterized. The degree of relaxation seems to heavily influence the targeting properties of dileucine-like motifs (Sitaram,2012). Motifs that do not satisfy the optimal consensus tend to prefer adaptins other than AP3, hence they are more likely to be trafficked to the cell surface. |
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Identification and structural determination of the M(3) muscarinic acetylcholine receptor basolateral sorting signal.
Iverson HA, Fox D 3rd, Nadler LS, Klevit RE, Nathanson NM
J Biol Chem 2005 Jul 1; 280 (26), 24568-75
PMID: 15870063
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The gamma/sigma1 and alpha/sigma2 hemicomplexes of clathrin adaptors AP-1 and AP-2 harbor the dileucine recognition site.
Doray B, Lee I, Knisely J, Bu G, Kornfeld S
Mol Biol Cell 2007 May; 18 (5), 1887-96
PMID: 17360967
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Similar [DE]XXXL[LI] motifs differentially target GLUT8 and GLUT12 in Chinese hamster ovary cells.
Flessner LB, Moley KH
Traffic 2009 Mar; 10 (3), 324-33
PMID: 19076329
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A structural explanation for the binding of endocytic dileucine motifs by
the AP2 complex.
Kelly BT, McCoy AJ, Spate K, Miller SE, Evans PR, Honing S, Owen DJ
Nature 2008 Dec 18; 456 (7224), 976-79
PMID: 19140243
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Conservation and diversification of dileucine signal recognition by adaptor protein (AP) complex variants.
Mattera R, Boehm M, Chaudhuri R, Prabhu Y, Bonifacino JS
J Biol Chem 2011 Jan 21; 286 (3), 2022-30
PMID: 21097499
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Differential recognition of a dileucine-based sorting signal by AP-1 and AP-3 reveals a requirement for both BLOC-1 and AP-3 in delivery of OCA2 to melanosomes.
Sitaram A, Dennis MK, Chaudhuri R, De Jesus-Rojas W, Tenza D, Setty SR, Wood CS, Sviderskaya EV, Bennett DC, Raposo G, Bonifacino JS, Marks MS
Mol Biol Cell 2012 Aug; 23 (16), 3178-92
PMID: 22718909
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Structural basis of HIV-1 Vpu-mediated BST2 antagonism via hijacking of the clathrin adaptor protein complex 1.
Jia X, Weber E, Tokarev A, Lewinski M, Rizk M, Suarez M, Guatelli J, Xiong Y
Elife 2014 Apr 29; 3 (0), e02362
PMID: 24843023
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The Role of the Clathrin Adaptor AP-1: Polarized Sorting and Beyond.
Nakatsu F, Hase K, Ohno H
Membranes (Basel) 2014 Nov 7; 4 (4), 747-63
PMID: 25387275
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Two Clathrin Adaptor Protein Complexes Instruct Axon-Dendrite Polarity.
Li P, Merrill SA, Jorgensen EM, Shen K
Neuron 2016 May 4; 90 (3), 564-80
PMID: 27151641
12 GO-Terms:
4 Instances for TRG_DiLeu_BaEn_2
(click table headers for sorting; Notes column: =Number of Switches, =Number of Interactions)
(click table headers for sorting; Notes column: =Number of Switches, =Number of Interactions)
Acc., Gene-, Name | Start | End | Subsequence | Logic | #Ev. | Organism | Notes |
---|---|---|---|---|---|---|---|
O15427 SLC16A3 MOT4_HUMAN |
441 | 447 | DSGVDLREVEHFLKAEPEKN | TP | 3 | Homo sapiens (Human) | |
P09958 FURIN FURIN_HUMAN |
782 | 788 | SEEDEGRGERTAFIKDQSAL | TP | 3 | Homo sapiens (Human) | |
P20309 CHRM3 ACM3_HUMAN |
275 | 281 | QASGTEAETENFVHPTGSSR | TP | 3 | Homo sapiens (Human) | |
Q9Y6R1 SLC4A4 S4A4_HUMAN |
1052 | 1058 | KIPMDIMEQQPFLSDSKPSD | TP | 3 | Homo sapiens (Human) |
Please cite:
The Eukaryotic Linear Motif resource: 2022 release.
(PMID:34718738)
ELM data can be downloaded & distributed for non-commercial use according to the ELM Software License Agreement
ELM data can be downloaded & distributed for non-commercial use according to the ELM Software License Agreement