AGS3-dependent trans-Golgi network membrane trafficking is essential for compaction in mouse embryos

Area of Science:

• Cell Biology
• Developmental Biology
• Molecular Biology

Background:

• Activator of G-protein signaling 3 (AGS3) regulates the trans-Golgi network and protein transport via Gαi binding.
• E-cadherin (Cdh1) accumulation at cell membranes drives early embryo compaction.
• The precise role of AGS3 in Cdh1 transport during early embryogenesis is unknown.

Purpose of the Study:

• To investigate the role of AGS3 in regulating E-cadherin (Cdh1) transport to the plasma membrane in early mouse embryos.
• To elucidate the mechanisms by which AGS3 influences trans-Golgi network dynamics and cargo trafficking.

Main Methods:

• AGS3 knockout in early mouse embryos using the Cas9-sgRNA system.
• Fluorescent protein tagging and tracking of trans-Golgi network protein 46 (TGN46) and TMED7.
• Analysis of Cdh1 accumulation, trans-Golgi network organization, and vesicle polarization.

Main Results:

• AGS3 knockout led to developmental arrest and fragmentation after the four-cell stage.
• Decreased Cdh1 accumulation at the membrane and dispersed trans-Golgi network/TMED7-positive vesicles were observed in AGS3-edited embryos.
• Increased Gαi1 expression rescued AGS3-overexpressed embryos, indicating a role for Gαi1.

Conclusions:

• AGS3 is essential for maintaining trans-Golgi network dynamics and TMED7-positive cargo transport, including Cdh1, to the cell surface.
• Proper AGS3 function is critical for successful early mouse embryo development and cell-cell adhesion.
• AGS3's regulation of Gαi1 signaling is implicated in its role in embryonic development.