The transport protein particle (TRAPP) complexes are multi-subunit tethering complexes involved in multiple pathways of vesicular traffic. TRAPP complexes exist in three forms, namely TRAPPI, TRAPPII and TRAPPIII. Each TRAPP complex is reported to localize to different subcellular compartments. Trs85p as a TRAPPIII specific subunits is involved in the cytosol to vacuole targeting (Cvt) pathway. Meanwhile, in a synthetic lethality screening against a COPI coatomer subunit mutant, mutations on TRS85 was identified, which suggest a role of Trs85p in the Golgi.

Through a negative genetic interaction study against TRS85, TRS85 was found to have negative genetic interactions with many genes that play a role in the Golgi traffic, which further suggests a novel role of Trs85p/TRAPPIII in the G...[ Read more ]

The transport protein particle (TRAPP) complexes are multi-subunit tethering complexes involved in multiple pathways of vesicular traffic. TRAPP complexes exist in three forms, namely TRAPPI, TRAPPII and TRAPPIII. Each TRAPP complex is reported to localize to different subcellular compartments. Trs85p as a TRAPPIII specific subunits is involved in the cytosol to vacuole targeting (Cvt) pathway. Meanwhile, in a synthetic lethality screening against a COPI coatomer subunit mutant, mutations on TRS85 was identified, which suggest a role of Trs85p in the Golgi.

Through a negative genetic interaction study against TRS85, TRS85 was found to have negative genetic interactions with many genes that play a role in the Golgi traffic, which further suggests a novel role of Trs85p/TRAPPIII in the Golgi other than in the preautophagosome. Also, the puncta pattern of GFP tagged Trs85p (which resembles Golgi localization) also indicates that beside preautophagosome, Trs85p should exists on other membrane compartments.

And it is believed that the distinct subcellular localization of each TRAPP complexes is determined by their own specific subunits. By a comprehensive study of Trs85p, several regions and residuals of Trs85p were identified to be essential for Trs85p functionality and TRAPP complex assembly.

Taken together, my studies revealed a novel role of Trs85p/TRAPPIII in the Golgi and the important functional domains of Trs85p in its functionality.