Vesicle transport through interaction with t-SNAREs homolog 1A (VTI1A)
The protein contains 217 amino acids for an estimated molecular weight of 25218 Da.
V-SNARE that mediates vesicle transport pathways through interactions with t-SNAREs on the target membrane. These interactions are proposed to mediate aspects of the specificity of vesicle trafficking and to promote fusion of the lipid bilayers. Involved in vesicular transport from the late endosomes to the trans-Golgi network. Along with VAMP7, involved in an non-conventional RAB1-dependent traffic route to the cell surface used by KCNIP1 and KCND2. May be involved in increased cytokine secretion associated with cellular senescence. (updated: April 1, 2015)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
This protein is predicted to be membranous by TOPCONS.
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Biological Process
Autophagy
Endoplasmic reticulum to Golgi vesicle-mediated transport
Golgi ribbon formation
Golgi to vacuole transport
Intra-Golgi vesicle-mediated transport
Protein targeting to vacuole
Retrograde transport, endosome to Golgi
Vesicle fusion with Golgi apparatus
Voluntary musculoskeletal movement
Cellular Component
Autophagosome
Clathrin-coated vesicle
Cytosol
Endoplasmic reticulum membrane
Endosome
ER to Golgi transport vesicle membrane
Golgi apparatus
Golgi membrane
Golgi stack
Integral component of membrane
Intracellular membrane-bounded organelle
Late endosome membrane
Neuron projection terminus
Neuronal cell body
Perinuclear region of cytoplasm
SNARE complex
Synaptic vesicle
Trans-Golgi network membrane
The reference OMIM entry for this protein is 614316
Vti1, s. cerevisiae, homolog of, a; vti1a
Vti1rp2 vti1a/tcf7l2 fusion gene, included
DESCRIPTION
VTI1A is a soluble N-ethylmaleimide-sensitive fusion protein attachment protein (SNAP; see 603215) receptor (SNARE) that functions in the transport of vesicles between the Golgi apparatus and the plasma membrane (Flowerdew and Burgoyne, 2009).CLONING
Xu et al. (1998) cloned mouse Vti1a, which they called Vti1rp2. The deduced 217-amino acid protein has 4 putative coiled-coil regions and a C-terminal transmembrane domain. The final coiled-coil region includes an ATP/GTP-binding motif A (P loop). Northern blot analysis detected a 2.6-kb transcript in all mouse tissues examined except testis, which expressed a 1.5-kb Vti1a transcript. Western blot analysis and differential extraction of fractionated rat liver membranes revealed that Vti1a was an integral Golgi membrane protein. By immunohistochemical analysis of HeLa cells, Flowerdew and Burgoyne (2009) found that human VTI1A showed a punctate vesicular distribution.GENE FUNCTION
Using protein pull-down assays, Xu et al. (1998) showed that mouse Vti1a interacted with alpha-SNAP (NAPA; 603215). Coimmunoprecipitation analysis revealed that Vti1a interacted with 2 distinct SNARE complexes that contained either syntaxin-5 (STX5; 603189) or syntaxin-6 (STX6; 603944). Immunodepletion of Vti1a from Vero monkey kidney cells interfered with plasma membrane trafficking of vesicular-stomatitis virus G protein (VSVG), resulting in accumulation of VSVG in the Golgi apparatus. Flowerdew and Burgoyne (2009) showed that potassium channel-interacting protein-1 (KCHIP1, or KCNIP1; 604660) interacted with the channel-forming Kv4.2 potassium channel subunit (KCND2; 605410) and was required for Kv4.2 trafficking to the plasma membrane. Using HeLa and mouse Neuro2A neuroblastoma cells, they found that KCHIP1 and Kv4.2 used an intracellular vesicle trafficking pathway that included VTI1A and VAMP7 (300053) and required the GTPase RAB1 (179508), which is shared with more conventional vesicle-trafficking pathways. Knockdown of VTI1A or VAMP7 inhibited transport of Kv4.2 and KCHIP1 to the plasma membrane, but it had no effect on membrane transport of VSVG.CYTOGENETICS
- VTI1A/TCF7L2 Fusion Gene Bass et al. (2011) reported whole-genome sequencing from 9 individuals with colorectal cancer (114500), including primary colorectal tumors and matched adjacent nontumor tissues, at an average of 30.7x and 31.9x coverage, respectively. They identified an average of 75 somatic rearrangements per tumor, including complex networks of translocations between pairs of chromosomes. Eleven rearrangements encode predicted in-frame fusion proteins, including a fusion of VTI1A and TCF7L2 (602278) found in 3 out of 97 colorectal cancers. Although TCF7L2 encodes TCF4, which cooperates with beta-catenin (116806) in colorectal carcinogenesis, the fusion lacks the TCF4 beta-catenin-binding domain. Bass et al. (2011) found a colorectal carcinoma cell line harboring the fusion gene to be dependent on VTI1A-TCF7L2 for anchorage-independent growth using RNA interference-mediated knockdown.MAPPING
Hartz (2011) mapped the VTI1A gene to chromosome 10q25.2 based on an alignment of the VTI1A sequence (GenBank GENBANK BC017052) with the genomic sequence (GRCh37). ... More on the omim web site
May 13, 2019: Protein entry updated
Automatic update: model status changed
Nov. 17, 2018: Protein entry updated
Automatic update: model status changed
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Oct. 27, 2017: Protein entry updated
Automatic update: model status changed
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 614316 was added.
Feb. 25, 2016: Protein entry updated
Automatic update: model status changed
Feb. 24, 2016: Protein entry updated
Automatic update: model status changed
Jan. 25, 2016: Protein entry updated
Automatic update: model status changed