TTPA alpha tocopherol transfer protein [Homo sapiens (human)] - Gene

Summary

Official Symbol: TTPAprovided by HGNC
Official Full Name: alpha tocopherol transfer proteinprovided by HGNC
Primary source: HGNC:HGNC:12404
See related: Ensembl:ENSG00000137561 MIM:600415; AllianceGenome:HGNC:12404
Gene type: protein coding
RefSeq status: REVIEWED
Organism: Homo sapiens
Lineage: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Also known as: ATTP; AVED; TTP1; alphaTTP
Summary: This gene encodes a soluble protein that binds alpha-trocopherol, a form of vitamin E, with high selectivity and affinity. This protein plays an important role in regulating vitamin E levels in the body by transporting vitamin E between membrane vesicles and facilitating the secretion of vitamin E from hepatocytes to circulating lipoproteins. Mutations in this gene cause hereditary vitamin E deficiency (ataxia with vitamin E deficiency, AVED) and retinitis pigmentosa. [provided by RefSeq, Nov 2009]
Expression: Biased expression in liver (RPKM 30.1) and colon (RPKM 1.4) See more
Orthologs: mouse all
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Genomic context

Location:: 8q12.3

Exon count:: 7

Annotation release	Status	Assembly	Chr	Location
RS_2023_10	current	GRCh38.p14 (GCF_000001405.40)	8	NC_000008.11 (63058409..63086053, complement)
RS_2023_10	current	T2T-CHM13v2.0 (GCF_009914755.1)	8	NC_060932.1 (63482981..63510623, complement)
105.20220307	previous assembly	GRCh37.p13 (GCF_000001405.25)	8	NC_000008.10 (63972047..63998612, complement)

Chromosome 8 - NC_000008.11 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Go to reference sequence details

Genomic Sequence:

Go to nucleotide: Graphics FASTA GenBank

Expression

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See details

Project title: HPA RNA-seq normal tissues
Description: RNA-seq was performed of tissue samples from 95 human individuals representing 27 different tissues in order to determine tissue-specificity of all protein-coding genes
BioProject: PRJEB4337
Publication: PMID 24309898
Analysis date: Wed Apr 4 07:08:55 2018

Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

Genetic heterogeneity within a consanguineous family involving TTPA and SETX genes.
Title: Genetic heterogeneity within a consanguineous family involving TTPA and SETX genes.
The tocopherol transfer protein mediates vitamin E trafficking between cerebellar astrocytes and neurons.
Title: The tocopherol transfer protein mediates vitamin E trafficking between cerebellar astrocytes and neurons.
alpha-Tocopherol transfer protein (alpha-TTP).
Title: α-Tocopherol transfer protein (α-TTP).
alpha-Tocopherol Transfer Protein Enhances alpha-Tocopherol Protective Effects in Lung A549 Cells.
Title: α-Tocopherol Transfer Protein Enhances α-Tocopherol Protective Effects in Lung A549 Cells.
Low TTP expression is associated with liver fibrosis.
Title: linc-SCRG1 accelerates liver fibrosis by decreasing RNA-binding protein tristetraprolin.
Authors show that a novel interaction between TTP and the CCR4-NOT subunit, CNOT9, is required for recruitment of the deadenylase complex. In addition to CNOT1, CNOT9 is now included in the identified CCR4-NOT subunits shown to interact with TTP.
Title: Tryptophan-Mediated Interactions between Tristetraprolin and the CNOT9 Subunit Are Required for CCR4-NOT Deadenylase Complex Recruitment.
Data show that, upon binding to its substrate, alpha-TTP acquires tendency to aggregation into thermodynamically stable high molecular weight oligomers with spheroidal particle formed by 24 protein monomers. Oligomerization is triggered by refolding of the N-terminus. These same oligomers are efficiently transported through an endothelial barrier and not through an epithelial one.
Title: Self-assembled α-Tocopherol Transfer Protein Nanoparticles Promote Vitamin E Delivery Across an Endothelial Barrier.
alphaTTP does not appear to regulate the uptake and intracellular localization of different vitamin E congeners in cultured liver cells.
Title: α-Tocopherol transfer protein does not regulate the cellular uptake and intracellular distribution of α- and γ-tocopherols and -tocotrienols in cultured liver cells.
These findings provide the basis for a proposed mechanistic model that describes TTP-facilitated trafficking of alpha-tocopherol through hepatocytes.
Title: Vitamin E and Phosphoinositides Regulate the Intracellular Localization of the Hepatic α-Tocopherol Transfer Protein.
Current results show that alphaTTP plays a role in endometrial carcinoma. Possibly endometrial cancer cells attempt to protect themselves from increasing oxidative stress by up-regulating alphaTTP.
Title: Alpha tocopherol transfer protein (αTTP) is expressed in endometrial carcinoma and is correlated with FIGO stage and 5-year survival.

Submit: New GeneRIF Correction See all GeneRIFs (30)

Phenotypes

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Find tests for this gene in the NIH Genetic Testing Registry (GTR)

Review eQTL and phenotype association data in this region using PheGenI

Associated conditions

Description	Tests
Familial isolated deficiency of vitamin E MedGen: C1848533 OMIM: 277460 GeneReviews: Hereditary Ataxia Overview, Ataxia with Vitamin E Deficiency	Compare labs

Variation

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See variants in ClinVar

See studies and variants in dbVar

See Variation Viewer (GRCh37.p13)

See Variation Viewer (GRCh38)

Interactions

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Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

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Gene Ontology Provided by GOA

Function	Evidence Code	Pubs
enables lipid transfer activity	IBA Inferred from Biological aspect of Ancestor more info
enables phosphatidylinositol bisphosphate binding	IBA Inferred from Biological aspect of Ancestor more info
enables phosphatidylinositol-3,4-bisphosphate binding	ISS Inferred from Sequence or Structural Similarity more info
enables phosphatidylinositol-4,5-bisphosphate binding	ISS Inferred from Sequence or Structural Similarity more info
enables protein binding	IPI Inferred from Physical Interaction more info	PubMed
enables vitamin E binding	IBA Inferred from Biological aspect of Ancestor more info
enables vitamin E binding	ISS Inferred from Sequence or Structural Similarity more info

Process	Evidence Code	Pubs
involved_in embryonic placenta development	IEA Inferred from Electronic Annotation more info
involved_in intermembrane lipid transfer	ISS Inferred from Sequence or Structural Similarity more info
involved_in lipid metabolic process	TAS Traceable Author Statement more info	PubMed
involved_in negative regulation of establishment of blood-brain barrier	IEA Inferred from Electronic Annotation more info
involved_in positive regulation of amyloid-beta clearance	IEA Inferred from Electronic Annotation more info
involved_in response to toxic substance	IEA Inferred from Electronic Annotation more info
involved_in vitamin E metabolic process	IBA Inferred from Biological aspect of Ancestor more info
involved_in vitamin transport	IBA Inferred from Biological aspect of Ancestor more info
involved_in vitamin transport	ISS Inferred from Sequence or Structural Similarity more info

Component	Evidence Code	Pubs
located_in cytosol	TAS Traceable Author Statement more info
is_active_in late endosome	IBA Inferred from Biological aspect of Ancestor more info

General protein information

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Preferred Names: alpha-tocopherol transfer protein

Names: alpha-TTP; tocopherol (alpha) transfer protein (ataxia (Friedreich-like) with vitamin E deficiency)

NCBI Reference Sequences (RefSeq)

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RefSeqs maintained independently of Annotated Genomes

These reference sequences exist independently of genome builds. Explain

These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

Genomic

NG_016123.1 RefSeqGene

Range

5001..31566

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GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

NM_000370.3 → NP_000361.1 alpha-tocopherol transfer protein isoform 1

See identical proteins and their annotated locations for NP_000361.1

Status: REVIEWED

Source sequence(s)

AC120042, BC041784, BC058000

Consensus CDS

CCDS6178.1

UniProtKB/Swiss-Prot

P49638, Q71V64

Related

ENSP00000260116.4, ENST00000260116.5

Conserved Domains (2) summary

smart01100
Location:40 → 73

CRAL_TRIO_N; CRAL/TRIO, N-terminal domain

pfam00650
Location:99 → 248

CRAL_TRIO; CRAL/TRIO domain
NM_001413414.1 → NP_001400343.1 alpha-tocopherol transfer protein isoform 2

Status: REVIEWED

Source sequence(s)

AC120042
NM_001413415.1 → NP_001400344.1 alpha-tocopherol transfer protein isoform 3

Status: REVIEWED

Source sequence(s)

AC120042
NM_001413416.1 → NP_001400345.1 alpha-tocopherol transfer protein isoform 4

Status: REVIEWED

Source sequence(s)

AC120042
NM_001413417.1 → NP_001400346.1 alpha-tocopherol transfer protein isoform 5

Status: REVIEWED

Source sequence(s)

AC120042
NM_001413418.1 → NP_001400347.1 alpha-tocopherol transfer protein isoform 6

Status: REVIEWED

Source sequence(s)

AC120042