Dictyostelium AMPKα regulates aggregate size and cell-type patterning.

Area of Science:

• Cellular and Molecular Biology
• Developmental Biology
• Biochemistry

Background:

• Starvation triggers multicellular development in Dictyostelium, involving cell aggregation.
• AMP-activated protein kinase (AMPK) is a conserved energy sensor crucial in cellular regulation.
• AMPK's role in Dictyostelium multicellular development, particularly during starvation-induced aggregation, is not fully understood.

Purpose of the Study:

• To investigate the function of AMPK in Dictyostelium discoideum multicellular development.
• To elucidate the impact of AMPK deletion on cell aggregation, development, and cell-type patterning.

Main Methods:

• Gene deletion of the AMPK alpha subunit (ampkα) in Dictyostelium.
• Analysis of aggregate formation, fruiting body development, and cell-type patterning in wild-type and mutant strains.
• Chimeric assays and conditioned media experiments to assess cell-cell interactions and signaling.

Main Results:

• Deletion of ampkα resulted in smaller, asynchronously developing aggregates and altered fruiting body morphology (small sori, long stalks).
• AMPK deficiency reduced aggregate size, even at low percentages in chimeras, and conditioned media from mutant cells induced smaller aggregates.
• ampkα cells displayed abnormal cell-type patterning with increased prestalk and reduced prespore regions, lacking a distinct boundary.

Conclusions:

• AMPK plays a critical role in regulating Dictyostelium cell aggregation size and developmental timing.
• The absence of AMPK disrupts normal cell-type differentiation and patterning during multicellular development.
• AMPK is essential for coordinating cellular behavior and achieving proper fruiting body formation in Dictyostelium.