Seroatlas · Human Serome Atlas

ITIH1

Inter-alpha-trypsin inhibitor heavy chain H1

Also known as: H1P, IATIH, ITIH, ITIH1_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P19827
Gene
ITIH1
Ensembl
ENSG00000055957
Chromosome
3
Canonical length
911 aa
Protein class
Plasma proteins, Predicted intracellular proteins, Predicted secreted proteins
Subcellular location
Vesicles
Secretome location
Secreted to blood

OverviewNCBI Gene

This gene encodes a member of the inter-alpha-trypsin inhibitor family of proteins. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed to generate the heavy chain of the inter-alpha-trypsin inhibitor complex, which is secreted by hepatocytes into the blood. The heavy chain also interacts with hyaluronan, and this interaction may play a role in ovulation and fertilization, and has been implicated in multiple inflammatory diseases. This gene is present in a gene cluster on chromosome 3. [provided by RefSeq, Nov 2015]

Canonical amino-acid sequenceUniProt

911 residues, UniProt reviewed canonical sequence.

>P19827|ITIH1
     1  MDGAMGPRGL LLCMYLVSLL ILQAMPALGS ATGRSKSSEK RQAVDTAVDG VFIRSLKVNC
    61  KVTSRFAHYV VTSQVVNTAN EAREVAFDLE IPKTAFISDF AVTADGNAFI GDIKDKVTAW
   121  KQYRKAAISG ENAGLVRASG RTMEQFTIHL TVNPQSKVTF QLTYEEVLKR NHMQYEIVIK
   181  VKPKQLVHHF EIDVDIFEPQ GISKLDAQAS FLPKELAAQT IKKSFSGKKG HVLFRPTVSQ
   241  QQSCPTCSTS LLNGHFKVTY DVSRDKICDL LVANNHFAHF FAPQNLTNMN KNVVFVIDIS
   301  GSMRGQKVKQ TKEALLKILG DMQPGDYFDL VLFGTRVQSW KGSLVQASEA NLQAAQDFVR
   361  GFSLDEATNL NGGLLRGIEI LNQVQESLPE LSNHASILIM LTDGDPTEGV TDRSQILKNV
   421  RNAIRGRFPL YNLGFGHNVD FNFLEVMSME NNGRAQRIYE DHDATQQLQG FYSQVAKPLL
   481  VDVDLQYPQD AVLALTQNHH KQYYEGSEIV VAGRIADNKQ SSFKADVQAH GEGQEFSITC
   541  LVDEEEMKKL LRERGHMLEN HVERLWAYLT IQELLAKRMK VDREERANLS SQALQMSLDY
   601  GFVTPLTSMS IRGMADQDGL KPTIDKPSED SPPLEMLGPR RTFVLSALQP SPTHSSSNTQ
   661  RLPDRVTGVD TDPHFIIHVP QKEDTLCFNI NEEPGVILSL VQDPNTGFSV NGQLIGNKAR
   721  SPGQHDGTYF GRLGIANPAT DFQLEVTPQN ITLNPGFGGP VFSWRDQAVL RQDGVVVTIN
   781  KKRNLVVSVD DGGTFEVVLH RVWKGSSVHQ DFLGFYVLDS HRMSARTHGL LGQFFHPIGF
   841  EVSDIHPGSD PTKPDATMVV RNRRLTVTRG LQKDYSKDPW HGAEVSCWFI HNNGAGLIDG
   901  AYTDYIVPDI F

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against ITIH1 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
Secreted
Secreted
Yes
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.26
Highest tissue expression
1,408 nTPM

Expression across tissuesHPA

Tissue

  • liver: 1,408 nTPM
  • blood vessel: 2.1 nTPM
  • spleen: 1.7 nTPM
  • adipose tissue: 0.8 nTPM
  • appendix: 0.5 nTPM
  • lymph node: 0.5 nTPM

Single-cell type

  • hepatocytes: 1,291 nCPM
  • cholangiocytes: 20 nCPM
  • kupffer cells: 8.2 nCPM
  • late spermatids: 3.7 nCPM
  • vascular smooth muscle cells: 1.9 nCPM
  • retinal amacrine cells: 1.4 nCPM

Immune cell

  • classical monocyte: 0.8 nTPM
  • intermediate monocyte: 0.2 nTPM
  • myeloid DC: 0.2 nTPM
  • NK-cell: 0.2 nTPM
  • total PBMC: 0.2 nTPM
  • basophil: 0 nTPM

Brain region

  • pons: 0.7 nTPM
  • cerebral cortex: 0.3 nTPM
  • basal ganglia: 0.2 nTPM
  • cerebellum: 0.2 nTPM
  • hippocampal formation: 0.2 nTPM
  • medulla oblongata: 0.2 nTPM

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)
1.23
gnomAD pLI
0
gnomAD missense Z
0.28
DepMap mean gene effect
-0.16
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% 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 ITIH1 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 ITIH1 as an antibody target. Whether an autoantibody or antibody against ITIH1 could matter depends on whether native ITIH1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

ITIH1 is annotated as secreted, so native ITIH1 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.

Annotation status

The present source text does not explicitly label ITIH1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/ITIH1. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...