Igf2

Igf2
Name	Insulin-like growth factor 2
Organism	Homo sapiens
Uniprot	P06213
Location	11p15.5

Igf2

Igf2 is a fetal growth factor encoded by a gene on human chromosome 11 that plays a central role in mammalian development, cellular proliferation, and metabolic regulation. First characterized in studies linking Frederick Sanger-era protein sequencing to endocrine biology, Igf2 has been studied alongside factors such as Insulin, Insulin-like growth factor 1, and receptors including IGF1R in contexts ranging from Beckwith–Wiedemann syndrome to cancer and metabolic disease. Research on Igf2 intersects with laboratories and institutions such as National Institutes of Health, Max Planck Society, and universities like Harvard University and University of Cambridge.

Structure and genomic organization

The Igf2 gene encodes a precursor peptide processed into a mature ligand structurally related to Insulin and Relaxin. The human locus maps to 11p15.5 within an imprinted domain that includes genes such as CDKN1C, H19, KCNQ1OT1, and SLC22A18. Genomic organization features multiple promoters and alternatively spliced transcripts identified in studies from groups at Cold Spring Harbor Laboratory and Wellcome Sanger Institute. Conserved elements adjacent to Igf2 include imprinting control regions bound by CTCF and chromatin marks noted by consortia including ENCODE. Comparative genomics shows conservation across mammals studied by teams at Howard Hughes Medical Institute and institutions involved in the Genome Project.

Expression and imprinting

Igf2 expression is predominantly paternal in many tissues due to imprinting mechanisms examined in classic experiments by researchers influenced by work from Susumu Ohno and laboratories using models from The Jackson Laboratory. Imprinting at the Igf2–H19 domain is regulated by differential methylation of imprinting control regions, interactions with CTCF, and long noncoding RNAs characterized in publications from Cold Spring Harbor Laboratory and European Molecular Biology Laboratory. Tissue-specific expression is dynamic during development in organs studied by teams at St. Jude Children's Research Hospital, Karolinska Institutet, and Johns Hopkins University and is responsive to signaling pathways involving factors studied at Massachusetts Institute of Technology.

Molecular function and signaling pathways

The mature Igf2 peptide binds with high affinity to receptors including IGF2R (mannose-6-phosphate receptor) and IGF1R, initiating signaling cascades characterized by activation of PI3K–AKT1 and MAPK pathways. Cross-talk with Insulin receptor isoforms and modulation by binding proteins such as IGFBP3 and IGFBP6 shape bioavailability; these interactions were elucidated in biochemical work from groups at University of Oxford and Yale University. Downstream effectors include regulators identified in cancer research centers like Memorial Sloan Kettering Cancer Center and molecular biology programs at University of California, San Francisco. Structural studies from facilities including European Synchrotron Radiation Facility and Argonne National Laboratory informed receptor–ligand models.

Role in development and growth

Igf2 is a principal fetal growth regulator implicated in placental development, organogenesis of tissues such as liver and muscle, and postnatal growth trajectories documented by pediatric research at Great Ormond Street Hospital and Children's Hospital of Philadelphia. Experimental ablation in murine models from researchers at Institut Pasteur and Cold Spring Harbor Laboratory produced phenotypes influencing body size, metabolic set points, and neurodevelopmental outcomes of interest to teams at University College London and University of Toronto. Studies correlating Igf2 expression with growth disorders involved collaborations with clinical centers like Mayo Clinic and population cohorts coordinated by National Institutes of Health.

Clinical significance and disease associations

Dysregulation of Igf2 imprinting or expression is implicated in congenital overgrowth syndromes such as Beckwith–Wiedemann syndrome and growth-restriction conditions associated with imprinting defects identified in genetic clinics including Great Ormond Street Hospital. Aberrant Igf2 signaling contributes to tumorigenesis in cancers studied at Dana–Farber Cancer Institute and Johns Hopkins Kimmel Cancer Center, with relevance to colorectal, hepatocellular, and pediatric sarcomas investigated by consortia including American Association for Cancer Research. Altered Igf2 pathways intersect with metabolic diseases researched at Imperial College London and Karolinska Institutet, and therapeutic strategies targeting IGF signaling have been explored in clinical trials coordinated by centers like National Cancer Institute.

Experimental models and research methods

Investigations of Igf2 employ murine knockout and conditional alleles generated at facilities such as The Jackson Laboratory and transgenic models developed with support from European Molecular Biology Laboratory. Techniques include allele-specific expression assays, methylation-sensitive analyses used in studies at Wellcome Trust Sanger Institute, receptor binding assays from structural biology groups at Stanford University, and single-cell transcriptomics applied in projects at Broad Institute. Human genetic studies leveraging cohorts curated by UK Biobank and Framingham Heart Study complement cellular models from laboratories at MIT and Cold Spring Harbor Laboratory.

Category:Growth factors