Seroatlas · Human Serome Atlas

MTTP

Microsomal triglyceride transfer protein large subunit

Also known as: ABL, MTP, MTP_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
P55157
Gene
MTTP
Ensembl
ENSG00000138823
Chromosome
4
Canonical length
894 aa
Protein class
Disease related genes, FDA approved drug targets, Human disease related genes, Metabolic proteins, Predicted intracellular proteins
Subcellular location
Endoplasmic reticulum,Cytosol
Secretome location
Intracellular and membrane

OverviewNCBI Gene

MTP encodes the large subunit of the heterodimeric microsomal triglyceride transfer protein. Protein disulfide isomerase (PDI) completes the heterodimeric microsomal triglyceride transfer protein, which has been shown to play a central role in lipoprotein assembly. Mutations in MTP can cause abetalipoproteinemia. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

894 residues, UniProt reviewed canonical sequence.

>P55157|MTTP
     1  MILLAVLFLC FISSYSASVK GHTTGLSLNN DRLYKLTYST EVLLDRGKGK LQDSVGYRIS
    61  SNVDVALLWR NPDGDDDQLI QITMKDVNVE NVNQQRGEKS IFKGKSPSKI MGKENLEALQ
   121  RPTLLHLIHG KVKEFYSYQN EAVAIENIKR GLASLFQTQL SSGTTNEVDI SGNCKVTYQA
   181  HQDKVIKIKA LDSCKIARSG FTTPNQVLGV SSKATSVTTY KIEDSFVIAV LAEETHNFGL
   241  NFLQTIKGKI VSKQKLELKT TEAGPRLMSG KQAAAIIKAV DSKYTAIPIV GQVFQSHCKG
   301  CPSLSELWRS TRKYLQPDNL SKAEAVRNFL AFIQHLRTAK KEEILQILKM ENKEVLPQLV
   361  DAVTSAQTSD SLEAILDFLD FKSDSSIILQ ERFLYACGFA SHPNEELLRA LISKFKGSIG
   421  SSDIRETVMI ITGTLVRKLC QNEGCKLKAV VEAKKLILGG LEKAEKKEDT RMYLLALKNA
   481  LLPEGIPSLL KYAEAGEGPI SHLATTALQR YDLPFITDEV KKTLNRIYHQ NRKVHEKTVR
   541  TAAAAIILNN NPSYMDVKNI LLSIGELPQE MNKYMLAIVQ DILRFEMPAS KIVRRVLKEM
   601  VAHNYDRFSR SGSSSAYTGY IERSPRSAST YSLDILYSGS GILRRSNLNI FQYIGKAGLH
   661  GSQVVIEAQG LEALIAATPD EGEENLDSYA GMSAILFDVQ LRPVTFFNGY SDLMSKMLSA
   721  SGDPISVVKG LILLIDHSQE LQLQSGLKAN IEVQGGLAID ISGAMEFSLW YRESKTRVKN
   781  RVTVVITTDI TVDSSFVKAG LETSTETEAG LEFISTVQFS QYPFLVCMQM DKDEAPFRQF
   841  EKKYERLSTG RGYVSQKRKE SVLAGCEFPL HQENSEMCKV VFAPQPDSTS SGWF

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against MTTP can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.25
Highest tissue expression
259 nTPM

Expression across tissuesHPA

Tissue

  • small intestine: 259 nTPM
  • liver: 249 nTPM
  • duodenum: 229 nTPM
  • kidney: 12 nTPM
  • testis: 9 nTPM
  • retina: 5.1 nTPM

Single-cell type

  • enterocytes: 775 nCPM
  • hepatocytes: 327 nCPM
  • müller glia: 130 nCPM
  • early spermatids: 56 nCPM
  • enteric transient amplifying cells: 45 nCPM
  • early primary spermatocytes: 44 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • white matter: 3.4 nTPM
  • midbrain: 3 nTPM
  • hypothalamus: 2.7 nTPM
  • medulla oblongata: 2.4 nTPM
  • spinal cord: 2.1 nTPM
  • thalamus: 2 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about MTTP.

Disease | AllUniProt

Conditions MTTP is implicated in, by any mechanism.

Disease | GeneticClinVar

181 pathogenic / likely-pathogenic of 1,245 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.59
gnomAD pLI
0
gnomAD missense Z
1.03
DepMap mean gene effect
0.02
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of MTTP in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads MTTP as an antibody target. Whether an autoantibody or antibody against MTTP could matter depends on whether native MTTP is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

MTTP is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label MTTP as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/MTTP. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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