Abstract
The insulin-like growth factor binding protein (IGFBP) family is a critical component of the insulin-like growth factor (IGF) system which regulate the biological actions of the IGFs and may also be capable of IGF-independent actions. To date, seven distinct IGFBPs have been described. Among these IGFBPs, IGFBPs-1-6 bind IGFs with high affinity, while only IGFBP-7 binds with low affinity. Recently, we have demonstrated that connective tissue growth factor (CTGF) also binds IGFs with low affinity, suggesting that a family of low-affinity IGFBPs, distinct from the high-affinity members, may exist, and together these constitute an IGFBP superfamily. IGFBPs have various biological roles. IGFBPs act not only as a carrier proteins, but also as a modulators of IGF actions by involving in IGF ligand-receptor interactions through influences on both the bioavailability and distribution of IGFs in the extracellular environment. In addition, some IGFBPs (IGFBPs-1, -3, and -5) appears to have intrinsic activity independent of IGFs. This review will focus on recent studies on the biological roles of IGFBPs in IGF-dependent and IGF-independent modes.
Original language | English (US) |
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Pages (from-to) | 85-96 |
Number of pages | 12 |
Journal | Experimental and Molecular Medicine |
Volume | 29 |
Issue number | 2 |
DOIs | |
State | Published - 1997 |
Keywords
- Connective tissue growth factor
- Insulin-like growth factor binding proteins
- Insulin-like growth factors
- Review literature
ASJC Scopus subject areas
- Biochemistry
- Molecular Medicine
- Molecular Biology
- Clinical Biochemistry