title: Differential selection of Golgi proteins by COPII Sec24 isoforms in procyclic Trypanosoma brucei.
abstract: The Sec24 subunit of the coat protein complex II (COPII) has been implicated in selecting newly synthesized cargo from the endoplasmic reticulum (ER) for delivery to the Golgi. The protozoan parasite, Trypanosoma brucei, contains two paralogs, TbSec24.1 and TbSec24.2, which were depleted using RNA interference in the insect form of the parasite. Depletion of either TbSec24.1 or TbSec24.2 resulted in growth arrest and modest inhibition of anterograde transport of the putative Golgi enzyme, TbGntB, and the secretory marker, BiPNAVRG-HA9. In contrast, depletion of TbSec24.1, but not TbSec24.2, led to reversible mislocalization of the Golgi stack proteins, TbGRASP and TbGolgin63. The latter accumulated in the ER. The localization of the COPI coatomer subunit, TbεCOP, and the trans Golgi network (TGN) protein, TbGRIP70, was largely unaffected, although the latter was preferentially lost from those Golgi that were not associated with the bilobe, a structure previously implicated in Golgi biogenesis. Together, these data suggest that TbSec24 paralogs can differentiate among proteins destined for the Golgi.
authors.affiliation: Max F. Perutz Laboratories, University of Vienna, Medical University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria.
authors.forename: Lars
authors.initials: L
authors.lastname: Demmel
authors.forename: Michael
authors.initials: M
authors.lastname: Melak
authors.forename: Harald
authors.initials: H
authors.lastname: Kotisch
authors.forename: Justin
authors.initials: J
authors.lastname: Fendos
authors.forename: Siegfried
authors.initials: S
authors.lastname: Reipert
authors.forename: Graham
authors.initials: G
authors.lastname: Warren
mesh_terms: D022181:COP-Coated Vesicles / Q000378:metabolism*; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000378:metabolism; D055785:Gene Knockdown Techniques / Q000379:methods; D006056:Golgi Apparatus / Q000378:metabolism*; D020033:Protein Isoforms; D021122:Protein Subunits; D021381:Protein Transport; D014346:Trypanosoma brucei brucei / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism* / Q000502:physiology
chemical_list: D020033:Protein Isoforms; D021122:Protein Subunits; D033921:Vesicular Transport Proteins