Vimentin intermediate filaments provide structural stability to the mammalian Golgi complex

Area of Science:

• Cell Biology
• Cytoskeletal Dynamics
• Organelle Structure

Background:

• The Golgi complex is a perinuclear organelle crucial for protein modification and transport.
• Golgi structure and position depend on microtubules and actin, but its relationship with intermediate filaments (IFs) is less understood.
• Vimentin intermediate filaments (IFs) are a key component of the cellular cytoskeleton.

Purpose of the Study:

• To investigate the physical association between the Golgi complex and vimentin IFs.
• To determine the functional role of vimentin IFs and the protein GORAB in Golgi structure and stability.

Main Methods:

• Immunofluorescence microscopy to visualize Golgi and vimentin IFs.
• Cell culture experiments using vimentin knockout cells and GORAB knockdown.
• Assessment of Golgi structure and dynamics upon treatment with brefeldin A and nocodazole.
• Cell culture on hydrogels of varying stiffness to study Golgi ribbon integrity.

Main Results:

• The Golgi complex is in close proximity to vimentin IFs in cultured cells.
• The trans-Golgi network protein GORAB physically associates with vimentin IFs.
• Loss of vimentin or GORAB had minor effects on steady-state Golgi structure.
• Vimentin knockout cells showed faster Golgi disassembly and slower reassembly after drug treatment.
• Vimentin loss reduced Golgi ribbon integrity on stiff substrates, an effect worsened by GORAB loss.

Conclusions:

• Vimentin IFs contribute significantly to the structural stability of the Golgi complex.
• GORAB plays a role in vimentin-mediated Golgi stability.
• The interplay between vimentin IFs and the Golgi is critical for maintaining organelle integrity, especially under mechanical stress.