High impact information on ea

• In ea(D) embryo extracts, we detect an Easter form corresponding to the free catalytic domain, which is never observed in wild type [1].
• Positive and negative regulation of Easter, a member of the serine protease family that controls dorsal-ventral patterning in the Drosophila embryo [2].
• Easter is the final protease in a serine protease cascade in which initial reaction steps appear not to be ventrally restricted, but where Easter activity is promoted ventrally through the action of a spatial cue at an unknown step in the pathway [3].
• An active form of Easter protease cleaves the Spätzle protein, generating a carboxyterminal polypeptide fragment which, when microinjected into the perivitelline space of a spätzle deficient embryo, directs production of ventrolateral pattern elements [4].
• Although in Drosophila the Easter protease processes the pro-Spätzle protein to generate the Toll ligand during development, the identification of the protease responsible for pro-Spätzle processing during the immune response has remained elusive for a decade [5].

Biological context of ea

• Biochemical interactions underlying the generation of the ventralising signal during Drosophila embryogenesis were investigated by the expression of recombinant Easter and Spätzle proteins [4].

References