ID3 Transcriptional regulator (lacking a basic DNA binding domain) which negatively regulates the basic helix-loop-helix (bHLH) transcription factors by forming heterodimers and inhibiting their DNA binding and transcriptional activity. Implicated in regulating a variety of cellular processes, including cellular growth, senescence, differentiation, apoptosis, angiogenesis, and neoplastic transformation. Involved in myogenesis by inhibiting skeletal muscle and cardiac myocyte differentiation and promoting muscle precursor cells proliferation. Inhibits the binding of E2A-containing protein complexes to muscle creatine kinase E-box enhancer. Regulates the circadian clock by repressing the transcriptional activator activity of the CLOCK-ARNTL/BMAL1 heterodimer. Expressed abundantly in lung, kidney and adrenal gland, but not in adult brain. Note: This description may include information from UniProtKB.
Protein type: DNA-binding; Transcription, coactivator/corepressor
Chromosomal Location of human Ortholog: 1p36.12
Cellular Component: 
Molecular Function:  DNA-binding transcription factor activity, RNA polymerase II-specific; leptomycin B binding; protein binding; protein dimerization activity; protein domain specific binding; transcription corepressor activity
Biological Process:  cellular response to leptomycin B; central nervous system development; epithelial cell differentiation; heart development; metanephros development; multicellular organism development; muscle organ development; negative regulation of DNA-binding transcription factor activity; negative regulation of myoblast differentiation; negative regulation of osteoblast differentiation; negative regulation of transcription by RNA polymerase II; negative regulation of transcription, DNA-templated; notochord development; odontogenesis; positive regulation of apoptotic process; regulation of DNA replication; response to wounding; transcription, DNA-templated
Reference #:  Q02535 (UniProtKB)
Alt. Names/Synonyms: 1R21; BHLHB25; Class B basic helix-loop-helix protein 25; DNA-binding protein inhibitor ID-3; HEIR-1; HEIR1; Helix-loop-helix protein HEIR-1; ID-like protein inhibitor HLH 1R21; ID3; Inhibitor of differentiation 3; Inhibitor of DNA binding 3; inhibitor of DNA binding 3, dominant negative helix-loop-helix protein; inhibitor of DNA binding 3, HLH protein
Gene Symbols: ID3
Molecular weight: 12,999 Da
Basal Isoelectric point: 5.55  Predict pI for various phosphorylation states
Protein-Specific Antibodies, siRNAs or Recombinant Proteins from Cell Signaling Technology® Total Proteins
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Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  cBioPortal  |  Wikipedia  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  RCSB PDB  |  Phospho.ELM  |  NetworKIN  |  GeneCards  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene