Easter (Ea)

Protein Structure: disregard
Activity: protease that produces mature Spatzle
Localization: Easter protease is found in the space that surrounds the embryo
Expression Pattern: Activated Easter protease is found in the ventral region of the space srrounding the embryo
Modifications: disregard
Stability: disregard
Targets of Action: A novel secreted protein is cleaved by Easter, to produce the ligand for Toll . This protein is called: _________

Spätzle (SPZ)

Protein Structure: 253 aa's. The spätzle gene encodes a novel secreted protein that requires activation by a proteolytic processing reaction, which is present in the space that surrounds the embryo.
Activity: Activated SPZ is the ligand for receptor called: _________
Localization: In the fluid surrounding the embryo
Expression Pattern: constitutive and secreted
Modifications: Requires proteolytic processing for activity
Stability: disregard
Targets of Action: interacts with the extracellular domain of a receptor called: ___________

Toll (TL)

Protein Structure: 1097 aa's. TL is an integral membrane protein with a cytoplasmic domain and a large extracellular domain that binds to a ligand that is abundant in fluid surrounding the ventral part of the embryo.
Activity: Structure suggests Toll is a receptor
Localization: membrane localized
Expression Pattern: TL is expressed in all embryo cells.
Modifications: disregard
Stability: disregard
Targets of Action: Ligand binding activates the signal transduction pathway through this protein kinase: _____________.

Pelle (Pll)

Protein Structure: 501 aa's. A protein kinase, so it adds a phosphate group to target proteins.
Activity: Serine/Threonine Protein kinase
Localization: cytoplasmic
Expression Pattern: Pll's activity depends on activation by a membrane receptor called (__________)
Modifications: disregard
Stability: disregard
Targets of Action: phosphorylates residues on the protein called: ____________.

 

Pelle (Pll)

Protein Structure: 501 aa's. A protein kinase, so it adds a phosphate group to target proteins.
Activity: Serine/Threonine Protein kinase
Localization: cytoplasmic
Expression Pattern: Pll's activity depends on activation by a membrane receptor called (__________)
Modifications: disregard
Stability: disregard
Targets of Action: phosphorylates residues on the protein called: ____________.

 

Cactus (Cact)

Protein Structure: Approx. 500 aa's. Cactus encodes a cytoplasmic protein with a region known to interact with other proteins.
Activity: Can binds other protein(s), and maintain them in the cytoplasm
Localization: Cactus is tenaciously cytoplasmic
Expression Pattern: Expressed constitutively
Modifications: disregard
Stability: Cactus is subject to digestion by cellular proteases, but only after it has been phosphorylated and then ubiquitinated.
Targets of Action: Cactus' primary role is connected with its binding and release of a transcription factor called: _______.

Dorsal (DL)

Protein Structure: 678 aa's. This protein is a transcription factor. Dorsal can sometimes be found bound to another protein called: ___________. In this state, Dorsal's activity as a transcription factor is ___________, because it is then localized in the ___________.
Activity: transcription factor
Localization: cytoplasm or nucleus
Expression Pattern: disregard
Modifications: disregard
Stability: disregard
Targets of Action: DL activates and represses genes responsible for differentiation along the dorsoventral axis. It does this ONLY after it accumulates in the cell's _____________.

 

Various target genes important in ventral development

Protein Structure: Many genes
Activity: disregard
Localization: Expressed primarily in cells along the venral part of the young embryo
Expression Pattern: Subject to repression by the dorsal-ventral pathway
Modifications: disregard
Stability: disregard
Mode of Action: Many genes are regulated by dorsal-ventral pathway.