Insulin-like growth factor-binding protein
| Insulin-like growth factor binding protein |
|||||||||
|---|---|---|---|---|---|---|---|---|---|
| File:PDB 1boe EBI.jpg
Structure of the IGF-binding domain of the insulin-like growth factor-binding protein-5 (IGFBP-5).[1]
|
|||||||||
| Identifiers | |||||||||
| Symbol | IGFBP | ||||||||
| Pfam | PF00219 | ||||||||
| InterPro | IPR000867 | ||||||||
| SMART | SM00121 | ||||||||
| PROSITE | PDOC00194 | ||||||||
| SCOP | 1boe | ||||||||
| SUPERFAMILY | 1boe | ||||||||
|
|||||||||
The Insulin-like growth factor-binding protein also known as IGFBP serves as a carrier protein for Insulin-like growth factor 1 (IGF-1).[2]
Function
Approximately 98% of IGF-1 is always bound to one of six binding proteins (IGF-BP). IGFBP-3, the most abundant protein, accounts for 80% of all IGF binding. IGF-1 binds to IGFBP-3 in a 1:1 molar ratio. IGF-BP also binds to IGF-1 inside the liver, allowing growth hormone to continuously act upon the liver to produce more IGF-1.
IGF binding proteins (IGFBPs) are proteins of 24 to 45 kDa. All six IGFBPs share 50% homology with each other and have binding affinities for IGF-I and IGF-II at the same order of magnitude as the ligands have for the IGF-IR.[3]
The IGFBPs help to lengthen the half-life of circulating IGFs in all tissues, including the prostate.[4] Individual IGFBPs may act to enhance or attenuate IGF signaling depending on their physiological context (i.e. cell type). Even with these similarities, some characteristics are different: chromosomal location, heparin binding domains, RGD recognition site, preference for binding IGF-I or IGF-II, and glycosylation and phosphorylation differences.[5] These structural differences can have a tremendous impact on how the IGFBPs interact with cellular basement membranes.
Family members
In humans, IGFBPs are transcribed from the following seven genes:
See also
References
<templatestyles src="Reflist/styles.css" />
Cite error: Invalid <references> tag; parameter "group" is allowed only.
<references />, or <references group="..." />External links
- Insulin-like growth factor binding proteins at the US National Library of Medicine Medical Subject Headings (MeSH)
<templatestyles src="Asbox/styles.css"></templatestyles>
 |
This biochemistry article is a stub. You can help Wikipedia by expanding it. |
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
