Insulin-like growth factor 2
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insulin-like growth factor 2 (somatomedin A)
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Identifiers | |
Symbol | IGF2 C11orf43 |
HUGO | 5466 |
Entrez | 3481 |
OMIM | 147470 |
RefSeq | NM_000612 |
UniProt | P01344 |
Other data | |
Locus | Chr. 11 p15.5 |
Insulin-like growth factor 2 (IGF-2) is a protein hormone similar in molecular structure to insulin. IGF2 plays an important role in fetal growth. It is sometimes produced in non-islet cell tumours, causing hypoglycemia (Doege-Potter syndrome).
Igf2 is an imprinted gene, meaning that it is differentially expressed depending on its allelic inheritance, i.e. maternal or paternal inheritance. On the maternal allele, Igf2 is repressed, while on the paternal allele it is expressed.
The protein CTCF plays heavily in the role of repressing the gene, by binding to the H-19 imprinting control region (ICR) along with Differentially-methylated Region-1 (DMR1) and MAR3. These three DNA sequences bind to CTCF in a way that limits downstream (towards 3') enhancer access to the Igf2 region. The mechanism in which CTCF binds to these regions is currently unknown, but could include either a direct DNA-CTCF interaction or it could possibly be mediated by other proteins.