Obstructor-A is required for epithelial extracellular matrix dynamics, exoskeleton function, and tubulogenesis.

Area of Science:

• Developmental Biology
• Molecular Biology
• Biochemistry

Background:

• Epithelial tissues form protective extracellular matrices (ECM) against environmental threats.
• In arthropods, the cuticle provides structural integrity and protection, but its development involves complex ECM regulation.
• The molecular mechanisms guarding the cuticle ECM from premature degradation during development are largely unknown.

Purpose of the Study:

• To investigate the role of the conserved obstructor multigene family, specifically Obstructor-A, in arthropod cuticle development and ECM dynamics.
• To elucidate the molecular interactions and mechanisms by which Obstructor-A regulates ECM protection.

Main Methods:

• Genetic analysis of obstructor-A loss-of-function mutants in arthropods.
• Biochemical assays to identify interacting partners of Obstructor-A.
• Characterization of extracellular matrix components and their modification.

Main Results:

• Loss of obstructor-A leads to severe defects in molting, wound healing, tube expansion, and larval growth.
• Obstructor-A forms a core complex with chitin, Knickkopf, and the chitin deacetylase Serpentine.
• Obstructor-A is essential for regulating the localization of Knickkopf and Serpentine in the ECM, thereby controlling chitin degradation and maturation.

Conclusions:

• Obstructor-A acts as a key coordinator of a protein complex that protects the cuticle ECM from premature degradation.
• This mechanism is vital for enabling exoskeletal molting, tube expansion, and maintaining epithelial integrity.
• The evolutionary conservation of Obstructor-A suggests a fundamental role in ECM protection across chitinous invertebrates.