TRG_Cilium_Arf4_1
Accession: | |
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Functional site class: | Ciliary targeting motifs |
Functional site description: | Ciliary transport is a specialised form of vesicular transport from the trans-Golgi network to the plasma membrane. It is responsible for the delivery of specialised membrane proteins like photoreceptors and ion channels to the cilia of vertebrate cells. Dysfunction in the delivery of ciliary cargo causes several human disorders (ciliopathies), such as retinal degeneration and polycystic kidneys. |
ELMs with same func. site: | TRG_Cilium_Arf4_1 TRG_Cilium_RVxP_2 |
ELM Description: | The QVxPA$ ciliary targeting motif was identified in rhodopsin, as a patch of 5 conserved aminoacids in the C-terminal region. It permits the transport of the photoreceptor from the trans-Golgi network, to the outer segment of the rod retinal cells through mediation of the small GTPases of the Arf family. |
Pattern: | QV.P.$ |
Pattern Probability: | 4.319e-07 |
Present in taxon: | Vertebrata |
Interaction Domain: |
Arf (PF00025)
ADP-ribosylation factor family
(Stochiometry: 1 : 1)
|
Abstract |
Cilia are hairlike cellular organelles with motile and sensory functions. They are assembled and maintained by intraflagellar transport (IFT), which uses microtubule-dependent motor proteins to mobilize ciliary cargo and to recycle components back to the basal body. Cilia compartmentalize receptors and signaling machinery, including effectors of phototransduction, olfaction, mechanosensation, as well as the crucial elements of signaling pathways (Inglis,2006). The vesicular trafficking required for the organization of the cilium is modulated by small GTPases of the Rab and Arf families (Jenkins,2007). A ciliary targeting motif has been extensively characterised in rhodopsin. Mutations in the C-terminal region of rhodopsin were first related to severe forms of retinitis pigmentosa in humans (Berson,1996). Shortly afterwards, it was discovered that such mutations disrupted the conserved terminal motif QV[SA]PA and resulted in aberrant sub-cellular localisation of rhodopsin (Deretic,1998). Subsequently it was shown that sorting and delivery of rhodopsin to the rod outer segments is achieved by the interaction of its C-terminal motif with the GTPase activating protein Arf4 (Deretic,2005). The association of the active Arf4-GTP with the trans-Golgi network membrane depends on the VxPx motif. Budding of the rhodopsin transport carrier vesicle is regulated by the Arf GAP ASAP1. It couples proof-reading of cargo incorporation to vesicle budding through the GTP hydrolysis of Arf4-GTP. Additionally, ASAP1 functions as a scaffold that incorporates other proteins (FIP3 and Rab11) necessary for the liberation of the carrier vesicle and its subsequent delivery to the rod outer segment (Mazelova,2009). A related ciliary targeting motif has been also identified in proteins like the cyclic nucleotide-gated channel subunit CNGB1b in olfactory neurons and polycystin-2 (PC2), a protein affected in polycystic kidney disease. While the involvement of the motif in the delivery of those proteins to the cilia of the respective cells has been experimentally verified (Geng,2006, Jenkins,2006), it is not yet clear if such transport requires Arf GTPases. |
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Regulation of sorting and post-Golgi trafficking of rhodopsin by its
C-terminal sequence QVS(A)PA.
Deretic D, Schmerl S, Hargrave PA, Arendt A, McDowell JH
Proc Natl Acad Sci U S A 1998 Sep 1; 95 (18), 10620-5
PMID: 9724753
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Piecing together a ciliome.
Inglis PN, Boroevich KA, Leroux MR
Trends Genet 2006 Sep; 22 (9), 491-500
PMID: 16860433
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Ciliary targeting motif VxPx directs assembly of a trafficking module
through Arf4.
Mazelova J, Astuto-Gribble L, Inoue H, Tam BM, Schonteich E, Prekeris R, Moritz OL, Randazzo PA, Deretic D
EMBO J 2009 Feb 4; 28 (3), 183-92
PMID: 19153612
11 GO-Terms:
1 Instance for TRG_Cilium_Arf4_1
(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 |
---|---|---|---|---|---|---|---|
P02699 RHO OPSD_BOVIN |
344 | 348 | GDDEASTTVSKTETSQVAPA | TP | 3 | Bos taurus (Cattle) |
Please cite:
ELM-the Eukaryotic Linear Motif resource-2024 update.
(PMID:37962385)
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