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Insulin receptor activation with transmembrane domain ligands
Jongsoon Lee1, Masaya Miyazaki2, Giulio R Romeo2
1From the Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215 jongsoon.lee@joslin.harvard.edu.
The Journal of Biological Chemistry
|May 29, 2014
Summary
Scientists discovered a new way to activate the insulin receptor (IR) using a peptide targeting its transmembrane domain, bypassing the usual ligand-binding site. This finding offers novel therapeutic strategies for insulin resistance.
Area of Science:
- Molecular Biology
- Cell Signaling
- Drug Discovery
Background:
- Hormone and growth factor receptor activation involves complementary surface interactions.
- Designing small molecules to mimic or block these interactions is challenging due to large binding surfaces.
Purpose of the Study:
- To investigate alternative activation pathways for the insulin receptor (IR).
- To explore targeting the IR transmembrane (TM) domain for receptor activation.
Main Methods:
- A 24-residue peptide mimicking the IR TM domain sequence was synthesized.
- The peptide's ability to activate IR and related receptors was tested.
- Activation requirements, including ATP-binding site and kinase activation loop, were assessed.
- Mutated IRs from patients with insulin resistance were used to test peptide activation.
Main Results:
- A peptide derived from the IR TM domain specifically activated the IR.
- This activation occurred independently of the canonical ligand-binding domain.
- The IR TM peptide activated IR in cells with mutated receptors resistant to insulin.
- Activation by the IR TM peptide required a functional ATP-binding site and kinase activation loop.
Conclusions:
- The insulin receptor can be activated via a novel pathway targeting the transmembrane domain.
- This bypasses the need for canonical ligand binding, offering new therapeutic avenues.
- The findings are significant for understanding insulin signaling and developing treatments for insulin resistance.
Keywords:
InsulinInsulin ReceptorPeptide HormonePeptide LigandReceptor ActivationReceptor Tyrosine KinaseTransmembrane DomainMore Related Videos
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