Description

Research Snapshot

What it is:
IGF-1 LR3 (Long R3 IGF-1) is a modified analog of insulin-like growth factor-1 (IGF-1) developed for laboratory research. Compared with native IGF-1, Long R3 IGF-1 has substantially reduced affinity for IGF-binding proteins (IGFBPs) while retaining activity at the IGF-1 receptor, making it useful for investigating IGF signaling with less regulation by binding proteins.

Researchers study it for:

• IGF-1 receptor signaling
• Cellular proliferation and differentiation
• Growth-factor biology
• Protein synthesis and cellular metabolism
• Muscle and tissue biology
• IGF-binding protein interactions
• Growth and developmental signaling

Target pathway(s):
IGF-1 Receptor (IGF-1R) • Receptor Tyrosine Kinase Signaling • IGF-Binding Proteins (IGFBPs) • Cellular Growth & Differentiation Pathways

What Is IGF-1 LR3?

IGF-1 LR3, also called Long R3 IGF-1, is an engineered analog of naturally occurring IGF-1.

Its structure differs from native IGF-1 through an amino-acid substitution at position three and an additional N-terminal peptide sequence. These modifications greatly reduce its affinity for IGF-binding proteins without eliminating its ability to activate the IGF-1 receptor (IGF-1R).

IGF-1R is a receptor tyrosine kinase involved in intracellular signaling related to cellular growth, survival, proliferation, differentiation, and metabolism. Because IGF-binding proteins normally influence the availability and biological activity of native IGF-1, Long R3 IGF-1 provides researchers with a useful tool for examining IGF-related signaling under altered IGFBP regulation.

Why Are Researchers Interested?

Scientific research investigates IGF-1 LR3 in relation to:

• IGF-1 receptor activation
• Cellular proliferation
• Cell differentiation
• Growth-factor signaling
• Muscle-cell and tissue biology
• IGF/IGFBP interactions
• Metabolic signaling
• Intestinal and other tissue-growth models

Long R3 IGF-1 has been used extensively in cell-culture and animal research. Studies have examined its effects in myogenic cells as well as intestinal and organ-growth models. Importantly, experimental responses can vary considerably by species, tissue, concentration, and study design.

Its reduced interaction with IGF-binding proteins makes IGF-1 LR3 particularly valuable as a laboratory research reagent for studying the IGF signaling system and distinguishing receptor-mediated activity from some of the regulatory effects produced by IGFBPs.