Q6DF80 · INSI1_XENLA

Function

function

Oxysterol-binding protein that mediates feedback control of cholesterol synthesis by controlling both endoplasmic reticulum to Golgi transport of scap and degradation of hmgcr. Acts as a negative regulator of cholesterol biosynthesis by mediating the retention of the SCAP-SREBP complex in the endoplasmic reticulum, thereby blocking the processing of sterol regulatory element-binding proteins (SREBPs). Binds oxysterol, including 25-hydroxycholesterol, regulating interaction with scap and retention of the SCAP-SREBP complex in the endoplasmic reticulum. In presence of oxysterol, interacts with scap, retaining the SCAP-SREBP complex in the endoplasmic reticulum, thereby preventing scap from escorting SREBPs to the Golgi. Sterol deprivation reduces oxysterol-binding, disrupting the interaction between insig1 and scap, thereby promoting Golgi transport of the SCAP-SREBP complex, followed by processing and nuclear translocation of SREBPs. Also regulates cholesterol synthesis by regulating degradation of hmgcr.

Features

Showing features for site.

125120406080100120140160180200220240
TypeIDPosition(s)Description
Site145Required for the recognition of 25-hydroxycholesterol

GO annotations

AspectTerm
Cellular Componentendoplasmic reticulum membrane
Molecular Functionoxysterol binding
Biological Processcholesterol metabolic process

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Insulin-induced gene 1 protein
  • Short names
    INSIG-1

Gene names

    • Name
      insig1

Organism names

  • Taxonomic identifier
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Amphibia > Batrachia > Anura > Pipoidea > Pipidae > Xenopodinae > Xenopus > Xenopus

Accessions

  • Primary accession
    Q6DF80

Proteomes

Organism-specific databases

Subcellular Location

Features

Showing features for topological domain, transmembrane.

TypeIDPosition(s)Description
Topological domain1-58Cytoplasmic
Transmembrane59-81Helical; Name=1
Topological domain82-100Extracellular
Transmembrane101-118Helical; Name=2
Topological domain119-133Cytoplasmic
Transmembrane134-156Helical; Name=3
Topological domain157-159Extracellular
Transmembrane160-178Helical; Name=4
Topological domain179-183Cytoplasmic
Transmembrane184-205Helical; Name=5
Topological domain206-219Extracellular
Transmembrane220-237Helical; Name=6
Topological domain238-251Cytoplasmic

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00002873901-251Insulin-induced gene 1 protein

Expression

Gene expression databases

    • 446436Expressed in kidney and 19 other cell types or tissues

Interaction

Subunit

Interacts with scap; interaction is direct and only takes place in the presence of sterols; it prevents interaction between scap and the coat protein complex II (COPII). Associates with the SCAP-SREBP complex; association is mediated via its interaction with scap and only takes place in the presence of sterols.

Structure

Family & Domains

Features

Showing features for motif.

TypeIDPosition(s)Description
Motif245-251KxHxx

Domain

The KxHxx motif mediates association with the coatomer complex.
Binds oxysterols in a pocket within their transmembrane domains and interacts with SCAP via transmembrane domains 3 and 4.

Sequence similarities

Belongs to the INSIG family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    251
  • Mass (Da)
    27,569
  • Last updated
    2004-08-16 v1
  • Checksum
    C4A3B397D33BAD88
MQTLEEHCWSCSCTRGRDKKGTKVSAWLARRVGKAMSSLNSLLSLAYSTLASSEGRSLIQRSLVLFTVGVFLALVLNLLQIQRNVTLFPEEVIATIFSSAWWVPPCCGTAAAVVGLLYPCIDSRIGEPHKFKREWASVMRCIAVFVGINHASAKLDFANNVQLSLTLAALSLGLWWTFDRSRSGLGLGITIAFLATLITQFLVYNGVYQYTSPDFLYIRSWLPCIFFSGGVTVGNIGRQLAMGSSEKTHGD

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
BC076862
EMBL· GenBank· DDBJ
AAH76862.1
EMBL· GenBank· DDBJ
mRNA

Genome annotation databases

Similar Proteins

Disclaimer

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