Insulin-like growth factor-binding protein 1 (IBP-1) also known as placental protein 12 (PP12) is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in humans is encoded by the IGFBP1 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

Function

This gene is a member of the Insulin-like growth factor-binding protein (IGFBP) family and encodes a protein with an IGFBP domain and a type-I thyroglobulin domain

Thyroglobulin domain

Thyroglobulin type-1 repeat is an evolutionary conserved protein domain.Thyroglobulin type 1 repeats are thought to be involved in the control of proteolytic degradation. The domain usually contains six conserved cysteines. These form three disulphide bridges...

. The protein binds both insulin-like growth factor

Insulin-like growth factor

The insulin-like growth factors are proteins with high sequence similarity to insulin. IGFs are part of a complex system that cells use to communicate with their physiologic environment...

s (IGFs) I and II and circulates in the plasma. Binding of this protein prolongs the half-life of the IGFs and alters their interaction with cell surface receptors. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.

Further reading