A conserved GTPase complex gates exocytosis for defence and parasitism across alveolates.

A conserved GTPase complex in alveolates regulates exocytosis, enabling defense and parasitism, with 3D structural insights revealing its activation mechanism.

• Why it matters: Understanding how eukaryotic cells control secretion outside metazoans is crucial for revealing fundamental biological processes and parasite virulence strategies.
• What they did: Researchers used genetic, cryo-electron tomography, and structural modeling on Tetrahymena thermophila and Toxoplasma gondii, focusing on a GTPase complex conserved across alveolates.
• The result: The complex maintains organelle readiness for secretion and activates upon stimulation, with apicomplexans using an apical vesicle for tighter control, shedding light on evolution and pathogenicity.