dc.description.abstract | To identify molecules that might act as down-stream effectors of hARL1, we used
hARL1(Q/L) as bait in a yeast two-hybrid screen of human fetal liver cDNA library. 43
positives were obtained and several distinct genes were chosen for further analysis. Among
them, golgin-245 (9 clones), ApoC2 (8 clones), Arfaptin 2 / POR1 (4 clones), ApoB (2
clones), and Sec10 (one clone) will be further characterized to support the their functional
interactions. We also constructed wild type hARL1 and hARL1-T/N to test whether
interaction of hARL1 and their interacting proteins is nucleotide-dependent. We also
found that hARL1 and golgin-245 bound to Golgi membranes, consistent with a function in
vesicular trafficking. Expression of putatively constitutively active mutant of hARL1,
ARL1(Q71L), in cells led to down-regulate golgin-245 bound to Golgi membranes. In vitro
protein-interaction assays showed that hARL1(Q71L) interacted with C-terminal of
golgin-245. How is sorting signal recognition regulated so that interaction with each
vesicle-receptor binding protein occurs only at the appropriate organelle? Cooperative
association of cargo, vesicle binding proteins, and additional factors into mutimeric,
trans-Golgi and/or lysosome-specific complexes will be investigated in this project. | en |