Insulin-like growth factor-binding protein-5 (IGFBP-5): a critical member of the IGF axis.
The six members of the insulin-like growth factor-binding protein family (IGFBP-1-6) are important components of the IGF (insulin-like growth factor) axis. In this capacity, they serve to regulate the activity of both IGF-I and -II polypeptide growth factors. The IGFBPs are able to enhance or inhibit the activity of IGFs in a cell- and tissue-specific manner. One of these proteins, IGFBP-5, also has an important role in controlling cell survival, differentiation and apoptosis. In this review, we report on the structural and functional features of the protein which are important for these effects. We also examine the regulation of IGFBP-5 expression and comment on its potential role in tumour biology, with special reference to work with breast cancer cells.
Beattie
James
J
Hannah Research Institute, Ayr KA6 5HL, Scotland, UK. j.beattie@hannah.ac.uk
Allan
Gordon J
GJ
Lochrie
Jennifer D
JD
Flint
David J
DJ
D000818:Animals; D005109:Extracellular Matrix / Q000378:metabolism; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009369:Neoplasms / Q000378:metabolism; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D013002:Somatomedins / Q000378:metabolism*
D018975:Insulin-Like Growth Factor Binding Protein 5; D013002:Somatomedins