Midbody Remnant Inheritance Is Regulated by the ESCRT Subunit CHMP4C

Area of Science:

• Cell Biology
• Epithelial Cell Biology
• Cell Division

Background:

• The inheritance of the midbody remnant (MBR) influences daughter cell asymmetry, impacting lumen and primary cilium formation in polarized epithelial cells.
• The precise mechanism and plasma membrane interaction of MBR inheritance remain poorly understood.

Purpose of the Study:

• To elucidate the physical connection between the plasma membrane and the inherited MBR.
• To identify the molecular mechanisms governing MBR inheritance.
• To determine the functional significance of the MBR-plasma membrane connection.

Main Methods:

• Correlative light and ultra-high-resolution scanning electron microscopy (UHR-SEM).
• Analysis of the ESCRT machinery, specifically the CHMP4C subunit.

Main Results:

• A membranous stalk physically links the MBR to the apical plasma membrane of epithelial cells.
• This stalk concentrates ESCRT machinery, with CHMP4C identified as essential for MBR inheritance.
• Depletion of CHMP4C significantly reduces the proportion of ciliated cells, highlighting the functional importance of the connection.

Conclusions:

• MBRs are directly connected to the plasma membrane through a stalk structure.
• The ESCRT subunit CHMP4C plays a critical role in maintaining the integrity of this MBR-plasma membrane connection.
• This connection is functionally important for processes such as primary cilium formation in epithelial cells.