Seroatlas · Human Serome Atlas

INSIG1

Insulin-induced gene 1 protein

Also known as: CL-6, INSI1_HUMAN, MGC1405

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

Protein identityUniProt · HPA

UniProt accession
O15503
Gene
INSIG1
Ensembl
ENSG00000186480
Chromosome
7
Canonical length
277 aa
Protein class
Plasma proteins, Predicted membrane proteins, Transporters
Subcellular location
Vesicles

OverviewNCBI Gene

This gene encodes an endoplasmic reticulum membrane protein that regulates cholesterol metabolism, lipogenesis, and glucose homeostasis. The encoded protein has six transmembrane helices which contain an effector protein binding site. It binds the sterol-sensing domains of sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), and is essential for the sterol-mediated trafficking of these two proteins. It promotes the endoplasmic reticulum retention of SCAP and the ubiquitin-mediated degradation of HMG-CoA reductase. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2016]

Canonical amino-acid sequenceUniProt

277 residues, UniProt reviewed canonical sequence.

>O15503|INSIG1
     1  MPRLHDHFWS CSCAHSARRR GPPRASAAGL AAKVGEMINV SVSGPSLLAA HGAPDADPAP
    61  RGRSAAMSGP EPGSPYPNTW HHRLLQRSLV LFSVGVVLAL VLNLLQIQRN VTLFPEEVIA
   121  TIFSSAWWVP PCCGTAAAVV GLLYPCIDSH LGEPHKFKRE WASVMRCIAV FVGINHASAK
   181  LDFANNVQLS LTLAALSLGL WWTFDRSRSG LGLGITIAFL ATLITQFLVY NGVYQYTSPD
   241  FLYIRSWLPC IFFSGGVTVG NIGRQLAMGV PEKPHSD

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against INSIG1 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
Other membrane
Secreted
No
Transmembrane segments
6
Mean surface accessibility (rSASA)
0.45
Highest tissue expression
527 nTPM

Expression across tissuesHPA

Tissue

  • liver: 527 nTPM
  • pancreas: 105 nTPM
  • choroid plexus: 99 nTPM
  • adipose tissue: 74 nTPM
  • salivary gland: 67 nTPM
  • spinal cord: 63 nTPM

Single-cell type

  • cdc: 1,591 nCPM
  • hepatocytes: 687 nCPM
  • epididymal principal cells: 536 nCPM
  • parietal cells: 506 nCPM
  • monocytes: 476 nCPM
  • esophageal apical cells: 414 nCPM

Immune cell

  • non-classical monocyte: 504 nTPM
  • intermediate monocyte: 273 nTPM
  • total PBMC: 85 nTPM
  • myeloid DC: 79 nTPM
  • T-reg: 77 nTPM
  • neutrophil: 63 nTPM

Brain region

  • white matter: 188 nTPM
  • pons: 139 nTPM
  • medulla oblongata: 138 nTPM
  • choroid plexus: 133 nTPM
  • midbrain: 119 nTPM
  • cerebral cortex: 115 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)
1.12
gnomAD pLI
0
gnomAD missense Z
1.9
DepMap mean gene effect
0.03
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% 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 INSIG1 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 INSIG1 as an antibody target. Whether an autoantibody or antibody against INSIG1 could matter depends on whether native INSIG1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

INSIG1 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 INSIG1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/INSIG1. 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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