CSB428H1F 2008 EXAM ANSWERS
Langevin et al 2.1
Rab11 labels apical RE.
Exocyst components (Sec5, 6, 10, 15) act together to tether RE with PM to coordinate plasma targeting of
DE-Cad and Arm. Specifically, Arm binds Sec10 and Rab11 binds Sec15. Without Sec, DE-Cad and Arm
accumulates in enlarged intracellular RE.
Isolated fly notum epithelial cells are incubated with DCAD2 antibody at 25 degrees Celsius for 30 minutes
to allow for endocytosis.
The DCAD2 antibody only targets extracellular domain of DE-Cad and only those DE-Cad below SJ since it
cannot pass through the SJ barrier to target apical DE-Cad.
Since DCAD2 antibody is found above SJ, this suggests basal DE-Cad is transcytosed to the apical side.
Chuang et al 3.1
SARA is a FYVE domain containing anchoring domain.
Assay 1: yeast-2-hybrid using rhodopsin C’ bait and bovine cDNA found human SARA interacted with bait.
Assay 2: GST pull down using GST labelled 39 C’ amino acids of rhodopsin and histadine labelled SARA.
Assay 3: anti-rhodopsin antibody co-immunoprecipitated with endogenous mouse SARA.
In rod photoreceptors, SARA is found in puncatate early endosome in apical cytoplasm of IS and basal
portion of proximal axoneme, connecting cilium and basal body.
Hypothesis: SARA bind phospholipids and mediates vesicule delivery of rhodopsin to OS and discgenesis.
Benton et al 4.1
Par1 phosphorylate Bazooka on two conserved serines, which is then bound by 14-3-3. This inhibits
Bazooka oligomerization and binding to aPKC and excludes Baz at lateral sides.
Mechanism 1: Par1 phosphorylates Baz on conserved S151 and S1085. 14-3-3 then binds Baz and inhibits