AMPK phosphorylates GBF1 for mitotic Golgi disassembly

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• The Golgi apparatus fragments during mitosis in mammalian cells, a process crucial for cell division.
• The precise molecular mechanisms driving Golgi fragmentation during mitosis remain largely unknown.

Purpose of the Study:

• To elucidate the molecular pathway regulating Golgi fragmentation during mitosis.
• To identify key proteins and signaling cascades involved in Golgi disassembly.

Main Methods:

• Utilized mammalian cell culture models.
• Investigated protein phosphorylation and activation states during mitosis.
• Examined protein-protein interactions and subcellular localization.
• Assessed the functional impact of signaling pathway components on Golgi structure and mitosis.

Main Results:

• AMP-activated protein kinase (AMPK) is activated upon entry into mitosis.
• Activated AMPK phosphorylates GBF1, a guanine nucleotide exchange factor (GEF).
• Phosphorylation causes GBF1 dissociation from the Golgi, inhibiting its Arf1-GEF activity.
• AMPK and GBF1 phosphorylation are essential for Golgi disassembly and mitosis progression.

Conclusions:

• AMPK-GBF1-Arf1 signaling pathway is identified as a key regulator of Golgi fragmentation.
• This pathway plays a critical role in coordinating Golgi disassembly with mitotic progression.
• Findings provide new insights into the molecular basis of cell division and organelle dynamics.