Premium
Plasmodium falciparum Sec24 marks transitional ER that exports a model cargo via a diacidic motif
Author(s) -
Lee Marcus C. S.,
Moura Pedro A.,
Miller Elizabeth A.,
Fidock David A.
Publication year - 2008
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2008.06250.x
Subject(s) - copii , brefeldin a , biology , endoplasmic reticulum , golgi apparatus , biogenesis , microbiology and biotechnology , plasmodium falciparum , copi , secretory pathway , genetics , gene , malaria , immunology
Summary Exit from the endoplasmic reticulum (ER) often occurs at distinct sites of vesicle formation known as transitional ER (tER) that are enriched for COPII vesicle coat proteins. We have characterized the organization of ER export in the malaria parasite, Plasmodium falciparum , by examining the localization of two components of the COPII machinery, PfSec12 and PfSec24a. PfSec12 was found throughout the ER, whereas the COPII cargo adaptor, PfSec24a, was concentrated at distinct foci that likely correspond to tER sites. These foci were closely apposed to cis ‐Golgi sites marked by PfGRASP–GFP, and upon treatment with brefeldin A they accumulated a model cargo protein via a process dependent on the presence of an intact diacidic export motif. Our data suggest that the cargo‐binding function of PfSec24a is conserved and that accumulation of cargo in discrete tER sites depends upon positive sorting signals. Furthermore, the number and position of tER sites with respect to the cis ‐Golgi suggests a co‐ordinated biogenesis of these domains.