Sec71 separates Golgi stacks in Drosophila S2 cells

Area of Science:

• Cell Biology
• Molecular Biology
• Developmental Biology

Background:

• Golgi stacks are fundamental cellular units that are typically dispersed in the cytoplasm.
• Brefeldin A (BFA) is a known inhibitor affecting Golgi structure and function.

Purpose of the Study:

• To investigate the mechanism by which Brefeldin A (BFA) induces the formation of BFA bodies.
• To identify the specific molecular targets of BFA involved in Golgi stack dynamics and polarized transport.

Main Methods:

• Live imaging of Drosophila S2 cells to observe Golgi stack behavior.
• Utilizing genome-edited cell lines with BFA-resistant and BFA-hypersensitive mutations in Sec71.
• Analyzing the effects of Sec71 impairment in Drosophila photoreceptors.

Main Results:

• Brefeldin A (BFA) induces BFA bodies, which are aggregates of Golgi stacks, trans-Golgi networks, and recycling endosomes.
• Golgi stacks merge by inhibited separation on their trans sides, forming BFA bodies.
• Sec71 is identified as the sole BFA target controlling Golgi stack separation; mutations in Sec71 alter BFA body formation.
• Sec71 impairment in fly photoreceptors leads to BFA body formation and disrupted polarized transport.

Conclusions:

• Sec71 is the critical mediator of BFA-induced Golgi stack aggregation and regulates Golgi stack separation.
• The findings elucidate a novel mechanism for BFA body formation and highlight Sec71's role in maintaining polarized transport in Drosophila.