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Rab GTPases and Exocyst in Plants |
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Viktor Žársky |
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Department of Plant
Physiology, Charles University, Vinicná 5, CZ-12844 Prague, CZECH
REPUBLIC |
| *email:
zarsky@ueb.cas.cz
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Oriented cell expansion in plant cells is regulated by members of Ras-related
superfamily of GTPases as in other eukaryots. Functional cycle of Rab family of protens is dependent on
C-terminal double-cysteine motif modification by geranylgeranyl hydrophobic moiety. We found plant-specific
features of Rab-geranylgeranyltransferase (RabGGTase) subunits and using molecular phylogenetic analysis we
proposed a new scenario of the GDI/REP superfamily of neurobiological proteins evolution. Analysis of a mutant
in one of the RabGGTase subunits points to the feedback regulation of photomorphogenesis by cell expansion. We
are studying exocyst complex in plants as a putative effector of small GTPases including Rab proteins. Our
biochemical as well as genetic evidence points to the exocyst involvement in plant cell polarity
regulation. |
