P55157 · MTP_HUMAN
- ProteinMicrosomal triglyceride transfer protein large subunit
- GeneMTTP
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids894 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Catalyzes the transport of triglyceride, cholesteryl ester, and phospholipid between phospholipid surfaces (PubMed:15897609, PubMed:16478722, PubMed:22236406, PubMed:23475612, PubMed:25108285, PubMed:26224785, PubMed:8876250, PubMed:8939939).
Required for the assembly and secretion of plasma lipoproteins that contain apolipoprotein B (PubMed:16478722, PubMed:23475612, PubMed:26224785, PubMed:8876250, PubMed:8939939).
May be involved in regulating cholesteryl ester biosynthesis in cells that produce lipoproteins (By similarity).
Required for the assembly and secretion of plasma lipoproteins that contain apolipoprotein B (PubMed:16478722, PubMed:23475612, PubMed:26224785, PubMed:8876250, PubMed:8939939).
May be involved in regulating cholesteryl ester biosynthesis in cells that produce lipoproteins (By similarity).
Catalytic activity
- a 1,2-diacyl-sn-glycero-3-phosphocholine(in) = a 1,2-diacyl-sn-glycero-3-phosphocholine(out)This reaction proceeds in the forward direction.
- a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(in) = a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(out)This reaction proceeds in the forward direction.
- a cholesterol ester(in) = a cholesterol ester(out)This reaction proceeds in the forward direction.
- a triacyl-sn-glycerol(in) = a triacyl-sn-glycerol(out)This reaction proceeds in the forward direction.
GO annotations
Keywords
- Biological process
- Ligand
Enzyme and pathway databases
Chemistry
Names & Taxonomy
Protein names
- Recommended nameMicrosomal triglyceride transfer protein large subunit
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionP55157
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Keywords
- Cellular component
Disease & Variants
Involvement in disease
Abetalipoproteinemia (ABL)
- Note
- DescriptionAn autosomal recessive disorder of lipoprotein metabolism. Affected individuals produce virtually no circulating apolipoprotein B-containing lipoproteins (chylomicrons, VLDL, LDL, lipoprotein(A)). Malabsorption of the antioxidant vitamin E occurs, leading to spinocerebellar and retinal degeneration.
- See alsoMIM:200100
Natural variants in ABL
Variant ID | Position(s) | Change | Description | |
---|---|---|---|---|
VAR_074553 | 169 | D>V | in ABL; no loss on localization to the endoplasmic reticulum; does not reduce interaction with APOB; inhibits interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion | |
VAR_074554 | 264 | G>R | in ABL; uncertain significance; does not reduce interaction with P4HB/PDI and APOB; does not reduce triglyceride transfer activity; dbSNP:rs1367079155 | |
VAR_074555 | 435 | L>H | in ABL; no loss on localization to the endoplasmic reticulum; inhibits triglyceride transfer activity | |
VAR_074556 | 528 | Y>H | in ABL; does not reduce interaction with P4HB/PDI and APOB; inhibits triglyceride transfer activity; dbSNP:rs1485375137 | |
VAR_074557 | 540 | R>C | in ABL; does not reduce interaction with P4HB/PDI and APOB; inhibits triglyceride transfer activity; dbSNP:rs372321643 | |
VAR_010642 | 540 | R>H | in ABL; no loss on localization to the endoplasmic reticulum; reduces interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion; dbSNP:rs199422220 | |
VAR_010643 | 590 | S>I | in ABL; no loss on localization to the endoplasmic reticulum; does not reduce interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion; dbSNP:rs199422222 | |
VAR_074558 | 649 | N>S | in ABL; uncertain significance; does not reduce interaction with P4HB/PDI and APOB; reduces triglyceride transfer activity | |
VAR_010644 | 746 | G>E | in ABL; no loss on localization to the endoplasmic reticulum; does not reduce interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion; dbSNP:rs767833468 | |
VAR_014019 | 780 | N>Y | in ABL; no loss on localization to the endoplasmic reticulum; does not reduce interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion; dbSNP:rs199422221 |
Features
Showing features for natural variant, mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Natural variant | VAR_014016 | 95 | in dbSNP:rs61733139 | |||
Sequence: Q → H | ||||||
Natural variant | VAR_052961 | 98 | in dbSNP:rs2306986 | |||
Sequence: E → D | ||||||
Natural variant | VAR_014017 | 128 | in dbSNP:rs3816873 | |||
Sequence: I → T | ||||||
Natural variant | VAR_052962 | 166 | in dbSNP:rs3792683 | |||
Sequence: N → S | ||||||
Natural variant | VAR_022658 | 168 | in dbSNP:rs61750974 | |||
Sequence: V → I | ||||||
Natural variant | VAR_074553 | 169 | in ABL; no loss on localization to the endoplasmic reticulum; does not reduce interaction with APOB; inhibits interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion | |||
Sequence: D → V | ||||||
Mutagenesis | 169 | No loss on localization to the endoplasmic reticulum and does not reduce interaction with APOB or P4HB/PDI, does partially reduce phospholipid or triglyceride transfer activity and apolipoprotein B secretion. | ||||
Sequence: D → E | ||||||
Mutagenesis | 187 | No loss on localization to the endoplasmic reticulum and does not reduce interaction with APOB, but inhibits interaction with P4HB/PDI, phospholipid or triglyceride transfer activity and apolipoprotein B secretion. | ||||
Sequence: K → L | ||||||
Mutagenesis | 187 | No loss on localization to the endoplasmic reticulum, does not reduce interaction with APOB or P4HB/PDI, partially inhibits triglyceride transfer activity, does not inhibit phospholipid transfer activity and apolipoprotein B secretion. | ||||
Sequence: K → R | ||||||
Mutagenesis | 189 | No loss on localization to the endoplasmic reticulum and does not reduce interaction with APOB, but inhibits interaction with P4HB/PDI, phospholipid or triglyceride transfer activity and apolipoprotein B secretion. | ||||
Sequence: K → L | ||||||
Mutagenesis | 189 | No loss on localization to the endoplasmic reticulum, does not reduce interaction with APOB or P4HB/PDI, partially inhibits triglyceride transfer activity, does not inhibit phospholipid transfer activity and apolipoprotein B secretion. | ||||
Sequence: K → R | ||||||
Natural variant | VAR_014018 | 244 | in dbSNP:rs17599091 | |||
Sequence: Q → E | ||||||
Natural variant | VAR_074554 | 264 | in ABL; uncertain significance; does not reduce interaction with P4HB/PDI and APOB; does not reduce triglyceride transfer activity; dbSNP:rs1367079155 | |||
Sequence: G → R | ||||||
Natural variant | VAR_010640 | 297 | does not inhibit apolipoprotein B secretion; dbSNP:rs2306985 | |||
Sequence: H → Q | ||||||
Natural variant | VAR_010641 | 384 | no loss on localization to the endoplasmic reticulum; does not reduce interaction with P4HB/PDI; reduces phospholipid or triglyceride transfer activity; does not inhibit apolipoprotein B secretion; dbSNP:rs17029215 | |||
Sequence: D → A | ||||||
Natural variant | VAR_074555 | 435 | in ABL; no loss on localization to the endoplasmic reticulum; inhibits triglyceride transfer activity | |||
Sequence: L → H | ||||||
Mutagenesis | 435 | No loss on localization to the endoplasmic reticulum. Inhibits triglyceride transfer activity. | ||||
Sequence: L → E | ||||||
Mutagenesis | 435 | No loss on localization to the endoplasmic reticulum. Does not inhibit triglyceride transfer activity. | ||||
Sequence: L → V | ||||||
Natural variant | VAR_074556 | 528 | in ABL; does not reduce interaction with P4HB/PDI and APOB; inhibits triglyceride transfer activity; dbSNP:rs1485375137 | |||
Sequence: Y → H | ||||||
Mutagenesis | 528 | Does not inhibit triglyceride transfer activity. | ||||
Sequence: Y → F | ||||||
Mutagenesis | 528 | Inhibits triglyceride transfer activity. | ||||
Sequence: Y → K | ||||||
Natural variant | VAR_074557 | 540 | in ABL; does not reduce interaction with P4HB/PDI and APOB; inhibits triglyceride transfer activity; dbSNP:rs372321643 | |||
Sequence: R → C | ||||||
Natural variant | VAR_010642 | 540 | in ABL; no loss on localization to the endoplasmic reticulum; reduces interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion; dbSNP:rs199422220 | |||
Sequence: R → H | ||||||
Mutagenesis | 540 | Strongly reduces triglyceride transfer activity. | ||||
Sequence: R → A | ||||||
Mutagenesis | 540 | Does not inhibit triglyceride transfer activity and apolipoprotein B secretion. | ||||
Sequence: R → K | ||||||
Natural variant | VAR_010643 | 590 | in ABL; no loss on localization to the endoplasmic reticulum; does not reduce interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion; dbSNP:rs199422222 | |||
Sequence: S → I | ||||||
Natural variant | VAR_074558 | 649 | in ABL; uncertain significance; does not reduce interaction with P4HB/PDI and APOB; reduces triglyceride transfer activity | |||
Sequence: N → S | ||||||
Natural variant | VAR_010644 | 746 | in ABL; no loss on localization to the endoplasmic reticulum; does not reduce interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion; dbSNP:rs767833468 | |||
Sequence: G → E | ||||||
Natural variant | VAR_014019 | 780 | in ABL; no loss on localization to the endoplasmic reticulum; does not reduce interaction with P4HB/PDI; inhibits phospholipid or triglyceride transfer activity; inhibits apolipoprotein B secretion; dbSNP:rs199422221 | |||
Sequence: N → Y | ||||||
Mutagenesis | 878 | Inhibits triglyceride transfer activity. | ||||
Sequence: C → S |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 1,169 variants from UniProt as well as other sources including ClinVar and dbSNP.
Keywords
- Disease
Organism-specific databases
Miscellaneous
Chemistry
Genetic variation databases
PTM/Processing
Features
Showing features for signal, chain, disulfide bond.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Signal | 1-18 | |||||
Sequence: MILLAVLFLCFISSYSAS | ||||||
Chain | PRO_0000041593 | 19-894 | Microsomal triglyceride transfer protein large subunit | |||
Sequence: VKGHTTGLSLNNDRLYKLTYSTEVLLDRGKGKLQDSVGYRISSNVDVALLWRNPDGDDDQLIQITMKDVNVENVNQQRGEKSIFKGKSPSKIMGKENLEALQRPTLLHLIHGKVKEFYSYQNEAVAIENIKRGLASLFQTQLSSGTTNEVDISGNCKVTYQAHQDKVIKIKALDSCKIARSGFTTPNQVLGVSSKATSVTTYKIEDSFVIAVLAEETHNFGLNFLQTIKGKIVSKQKLELKTTEAGPRLMSGKQAAAIIKAVDSKYTAIPIVGQVFQSHCKGCPSLSELWRSTRKYLQPDNLSKAEAVRNFLAFIQHLRTAKKEEILQILKMENKEVLPQLVDAVTSAQTSDSLEAILDFLDFKSDSSIILQERFLYACGFASHPNEELLRALISKFKGSIGSSDIRETVMIITGTLVRKLCQNEGCKLKAVVEAKKLILGGLEKAEKKEDTRMYLLALKNALLPEGIPSLLKYAEAGEGPISHLATTALQRYDLPFITDEVKKTLNRIYHQNRKVHEKTVRTAAAAIILNNNPSYMDVKNILLSIGELPQEMNKYMLAIVQDILRFEMPASKIVRRVLKEMVAHNYDRFSRSGSSSAYTGYIERSPRSASTYSLDILYSGSGILRRSNLNIFQYIGKAGLHGSQVVIEAQGLEALIAATPDEGEENLDSYAGMSAILFDVQLRPVTFFNGYSDLMSKMLSASGDPISVVKGLILLIDHSQELQLQSGLKANIEVQGGLAIDISGAMEFSLWYRESKTRVKNRVTVVITTDITVDSSFVKAGLETSTETEAGLEFISTVQFSQYPFLVCMQMDKDEAPFRQFEKKYERLSTGRGYVSQKRKESVLAGCEFPLHQENSEMCKVVFAPQPDSTSSGWF | ||||||
Disulfide bond | 174↔194 | |||||
Sequence: CKVTYQAHQDKVIKIKALDSC |
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Tissue specificity
Liver and small intestine. Also found in ovary, testis and kidney.
Induction
Positively regulated by cholesterol and negatively regulated by insulin.
Gene expression databases
Organism-specific databases
Interaction
Subunit
Heterodimer; heterodimerizes with the protein disulfide isomerase (P4HB/PDI) (PubMed:16478722, PubMed:23475612, PubMed:25108285, PubMed:26224785).
Interacts with APOB (PubMed:25108285, PubMed:26224785, PubMed:27206948).
Interacts with PRAP1 (By similarity).
Interacts with APOB (PubMed:25108285, PubMed:26224785, PubMed:27206948).
Interacts with PRAP1 (By similarity).
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
BINARY | P55157 | APOB P04114 | 4 | EBI-11614052, EBI-3926040 | |
XENO | P55157 | PDIA3 Q4VIT4 | 5 | EBI-11614052, EBI-22054129 |
Protein-protein interaction databases
Chemistry
Miscellaneous
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 28-659 | Vitellogenin | ||||
Sequence: LNNDRLYKLTYSTEVLLDRGKGKLQDSVGYRISSNVDVALLWRNPDGDDDQLIQITMKDVNVENVNQQRGEKSIFKGKSPSKIMGKENLEALQRPTLLHLIHGKVKEFYSYQNEAVAIENIKRGLASLFQTQLSSGTTNEVDISGNCKVTYQAHQDKVIKIKALDSCKIARSGFTTPNQVLGVSSKATSVTTYKIEDSFVIAVLAEETHNFGLNFLQTIKGKIVSKQKLELKTTEAGPRLMSGKQAAAIIKAVDSKYTAIPIVGQVFQSHCKGCPSLSELWRSTRKYLQPDNLSKAEAVRNFLAFIQHLRTAKKEEILQILKMENKEVLPQLVDAVTSAQTSDSLEAILDFLDFKSDSSIILQERFLYACGFASHPNEELLRALISKFKGSIGSSDIRETVMIITGTLVRKLCQNEGCKLKAVVEAKKLILGGLEKAEKKEDTRMYLLALKNALLPEGIPSLLKYAEAGEGPISHLATTALQRYDLPFITDEVKKTLNRIYHQNRKVHEKTVRTAAAAIILNNNPSYMDVKNILLSIGELPQEMNKYMLAIVQDILRFEMPASKIVRRVLKEMVAHNYDRFSRSGSSSAYTGYIERSPRSASTYSLDILYSGSGILRRSNLNIFQYIGKAGL |
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence & Isoform
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
This entry describes 2 isoforms produced by Alternative splicing.
P55157-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- Name1
- Length894
- Mass (Da)99,351
- Last updated1996-10-01 v1
- ChecksumB20260C136BDAB9F
P55157-2
- Name2
Computationally mapped potential isoform sequences
There are 3 potential isoforms mapped to this entry
Features
Showing features for alternative sequence, sequence conflict.
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
X75500 EMBL· GenBank· DDBJ | CAA53217.1 EMBL· GenBank· DDBJ | mRNA | ||
X59657 EMBL· GenBank· DDBJ | CAA42200.1 EMBL· GenBank· DDBJ | mRNA | ||
X83013 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83014 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83015 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83016 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83017 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83018 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83019 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83020 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83021 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83022 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83023 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83024 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83025 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83026 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83027 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83028 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83029 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X83030 EMBL· GenBank· DDBJ | CAA58142.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AK290793 EMBL· GenBank· DDBJ | BAF83482.1 EMBL· GenBank· DDBJ | mRNA | ||
AC083902 EMBL· GenBank· DDBJ | - | Genomic DNA | No translation available. | |
BC062696 EMBL· GenBank· DDBJ | AAH62696.1 EMBL· GenBank· DDBJ | mRNA | ||
BC125110 EMBL· GenBank· DDBJ | AAI25111.1 EMBL· GenBank· DDBJ | mRNA | ||
BC125111 EMBL· GenBank· DDBJ | AAI25112.1 EMBL· GenBank· DDBJ | mRNA |