Discs-Large and Strabismus are functionally linked to plasma membrane formation.

Area of Science:

• Developmental Biology
• Cell Biology
• Genetics

Background:

• Early embryogenesis requires extensive vesicle transport for cell boundary formation.
• The Discs-Large (Dlg) tumor suppressor and Strabismus (Stbm)/Van Gogh (Vang) integral membrane protein are key players in cellular organization.

Purpose of the Study:

• To investigate the role of the Discs-Large (Dlg) and Strabismus (Stbm) complex in plasma membrane formation during Drosophila embryogenesis.
• To elucidate the mechanism by which Dlg and Stbm interact to regulate membrane trafficking.

Main Methods:

• Genetic analysis of dlg and stbm mutants in Drosophila melanogaster.
• Analysis of protein localization and interactions using co-expression and vesicle association studies.
• Investigating the effects of Dlg and Stbm overexpression on plasma membrane formation.

Main Results:

• Mutations in dlg or stbm resulted in severe defects in plasma membrane formation.
• Overexpression of Dlg and Stbm synergistically led to excessive plasma membrane formation.
• Co-expression of Stbm and the mammalian Dlg homologue SAP97/hDlg promoted SAP97 translocation to post-Golgi vesicles and the plasma membrane, dependent on Stbm-SAP97 interaction.

Conclusions:

• A functional complex between Discs-Large (Dlg) and Strabismus (Stbm) is essential for plasma membrane formation in early Drosophila embryogenesis.
• The Dlg-Stbm complex mediates the recruitment of membrane components from internal membranes to sites of new plasma membrane formation.
• This mechanism highlights the importance of protein complex formation in regulating membrane trafficking and cellular architecture during development.