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The R ab GTP ase YPT ‐1 associates with G olgi cisternae and S pitzenkörper microvesicles in N eurospora crassa
Author(s) -
SánchezLeón Eddy,
Bowman Barry,
Seidel Constanze,
Fischer Reinhard,
Novick Peter,
Riquelme Meritxell
Publication year - 2015
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/mmi.12878
Subject(s) - microvesicles , biology , microbiology and biotechnology , microvesicle , biochemistry , microrna , gene
Summary Vesicle traffic involves budding, transport, tethering and fusion of vesicles with acceptor membranes. GTP ‐bound small R ab GTP ases interact with the membrane of vesicles, promoting their association with other factors before their subsequent fusion. Filamentous fungi contain at their hyphal apex the S pitzenkörper ( S pk), a multivesicular structure to which vesicles concentrate before being redirected to specific cell sites. The regulatory mechanisms ensuring the directionality of the vesicles that travel to the S pk are still unknown. Hence, we analyzed YPT ‐1, the N eurospora crassa homologue of S accharomyces cerevisiae Y pt1p ( R ab1), which regulates different secretory pathway events. Laser scanning confocal microscopy revealed fluorescently tagged YPT ‐1 at the S pk and putative G olgi cisternae. Co‐expression of YPT ‐1 and predicted post‐ G olgi R ab GTP ases showed YPT ‐1 confined to the S pk microvesicular core, while SEC ‐4 ( R ab8) and YPT ‐31 ( R ab11) occupied the S pk macrovesicular peripheral layer, suggesting that trafficking and organization of macro and microvesicles at the S pk are regulated by distinct R abs. Partial colocalization of YPT ‐1 with USO ‐1 (p115) and SEC ‐7 indicated the additional participation of YPT ‐1 at early and late G olgi trafficking steps.