insulin-like growth factor 2; IGF-2; somatomedin-A; contains: insulin-like growth factor 2 Ala-25 del; contains: preptin (IGF2)

Function

• insulin-like growth factors possess growth-promoting activity
  • in vitro, they are potent mitogens for cultured cells
• IGF2 is influenced by placental lactogen & may play a role in fetal development
• undergoes glucose-mediated co-secretion with insulin, & acts as physiological amplifier of glucose-mediated insulin secretion
• exhibits osteogenic properties by increasing osteoblast mitogenic activity through phosphoactivation of MAPK1 & MAPK3

Structure

• O-glycosylated with a core 1 or possibly core 8 glycan
• belongs to the insulin family
• mass=7469.4 daltons (IGF2)

Compartment

secreted

Alternative splicing

named isoforms=2

Pathology

• epigenetic changes of DNA hypomethylation in the IGF2 gene are a cause of Silver-Russell syndrome
• mRNA expression in lymphocytes is more common in patients with colorectal carcinoma than in the general polulation:
  • family history of colorectal carcinoma (5.2 fold increase)
  • adenomas (3.5 fold increase)
  • colorectal carcinoma (22 fold increase)

Genetics

• the IGF2 gene is an imprinted gene

Polymorphism

• genetic variations in IGF2 are associated with body mass index (BMI)

Laboratory

• IGF-2 expression in lymphocytes may become a useful test in screening for colorectal carcinoma

More general terms

• somatomedin
• peptide precursor
• multisubunit protein

Additional terms

• insulin-like growth factor [IGF]-2 receptor (CD222, somatomedin MSA receptor, cation-independent mannose-6-phosphate receptor, MPR 300, CI-MPR, M6PR, MPRI, IGF2R)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=3481
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:3481
• OMIM: https://mirror.omim.org/entry/147470
• OMIM: https://mirror.omim.org/entry/180860
• UniProt: http://www.uniprot.org/uniprot/P01344.html