The Aβ42 Peptide and IAPP Physically Interact in a Yeast-Based Assay.

Area of Science:

• Biochemistry
• Neuroscience
• Cell Biology

Background:

• Type 2 diabetes mellitus (T2DM) is associated with islet amyloid polypeptide (IAPP) aggregation.
• Alzheimer's disease (AD) is characterized by amyloid-beta (Aβ) aggregation.
• A correlation exists between T2DM and increased AD incidence, but the underlying mechanism is unclear.

Purpose of the Study:

• To investigate the interaction between IAPP and Aβ42 peptides using a yeast model.
• To determine if IAPP aggregates interact with Aβ42 or PrP aggregates in a cellular environment.

Main Methods:

• Utilized a yeast-based model system.
• Employed fluorescently tagged IAPP to observe aggregation.
• Applied Förster Resonance Energy Transfer (FRET) to study molecular interactions.
• Assessed co-localization and physical interaction of IAPP and Aβ42 aggregates.

Main Results:

• Fluorescently tagged IAPP formed detergent-resistant aggregates in yeast cells.
• IAPP and Aβ42 aggregates were shown to co-localize and physically interact within yeast cells.
• No interaction was observed between IAPP and PrP aggregates in the yeast system, indicating specificity.

Conclusions:

• Confirmed a direct physical interaction between IAPP and Aβ42 aggregates in a living cell.
• Hypothesize that this IAPP-Aβ42 interaction may seed Aβ42 aggregation in T2DM patients.
• This interaction could be a key mechanism contributing to the development of Alzheimer's disease in individuals with type 2 diabetes.