The insulin like growth factors (IGFs) are the major growth- promoting factors in the plasma.
IGFs are secreted by a variety of cells and exert a multitude of effects on cellular survival, growth and differentiation.
The A and B domains of IGFs are identical to insulin.
IGF initiates their biological action through binding to the type IGF receptor (IGF-1R), a heterotrimeric protein complex with a tyrosine kinase activity.
The IGF-IIR lacks the kinase activity and is actually identical to the mannose- 6-phophate receptor.
Unlike most other peptide hormones, IGFs are complexed with specific binding proteins in the plasma known IGF Binding proteins (IGFBPs).
At least 6 related IGFBPs (IGFBP1-6) have been well characterized.
Recently, IGFBP-7/Mac25/prostacyclin- stimulating factor (PSF)/tumor adhesion factor (TAF) was originally identified as a cDNA derived from leptomeninges.
These proteins are present in plasma in high concentration as compared to the membrane IGFRs.
Therefore, IGFBPs have the potential to modulate the IGF action.
IGFBPs have been shown to either inhibit or stimulate the IGF effects.
The primary structures of mammalian IGFBPs appear to contain three distinct domains of roughly equivalent sizes: the conserved N-terminal domain, the highly variable mid region, and the conserved C-terminal domain.
Human IGFBPs share approximately 36% identity.
Recently several groups of cysteine-rich proteins with discrete, but striking, structural and functional similarities to the IGFBPs.
This has led to the proposal of an IGFBP superfamily, comprised of the IGFBPs and these IGFBP-related proteins (IGFBP-rP1-9).
Applications:Suitable for use in Western Blot.
Other applications not tested.
Recommended Dilution:Optimal dilutions to be determined by the researcher.
