Interactions between Transport Protein Particle (TRAPP) complexes and Rab GTPases in Arabidopsis

Media type: E-Article
Title: Interactions between Transport Protein Particle (TRAPP) complexes and Rab GTPases in Arabidopsis
Contributor: Kalde, Monika; Elliott, Liam; Ravikumar, Raksha; Rybak, Katarzyna; Altmann, Melina; Klaeger, Susan; Wiese, Christian; Abele, Miriam; Al, Benjamin; Kalbfuß, Nils; Qi, Xingyun; Steiner, Alexander; Meng, Chen; Zheng, Huanquan; Kuster, Bernhard; Falter‐Braun, Pascal; Ludwig, Christina; Moore, Ian; Assaad, Farhah F.
Published: Wiley, 2019
Published in: The Plant Journal, 100 (2019) 2, Seite 279-297
Language: English
DOI: 10.1111/tpj.14442
ISSN: 0960-7412; 1365-313X
Keywords: Cell Biology ; Plant Science ; Genetics
Origination:
Footnote:
Description: <jats:title>Summary</jats:title><jats:p>Transport Protein Particle <jats:styled-content style="fixed-case">II</jats:styled-content> (<jats:styled-content style="fixed-case">TRAPPII</jats:styled-content>) is essential for exocytosis, endocytosis, protein sorting and cytokinesis. In spite of a considerable understanding of its biological role, little information is known about Arabidopsis <jats:styled-content style="fixed-case">TRAPPII</jats:styled-content> complex topology and molecular function. In this study, independent proteomic approaches initiated with <jats:styled-content style="fixed-case">TRAPP</jats:styled-content> components or Rab‐A <jats:styled-content style="fixed-case">GTP</jats:styled-content>ase variants converge on the <jats:styled-content style="fixed-case">TRAPPII</jats:styled-content> complex. We show that the Arabidopsis genome encodes the full complement of 13 <jats:styled-content style="fixed-case">TRAPPC</jats:styled-content> subunits, including four previously unidentified components. A dimerization model is proposed to account for binary interactions between <jats:styled-content style="fixed-case">TRAPPII</jats:styled-content> subunits. Preferential binding to dominant negative (<jats:styled-content style="fixed-case">GDP</jats:styled-content>‐bound) versus wild‐type or constitutively active (<jats:styled-content style="fixed-case">GTP</jats:styled-content>‐bound) <jats:styled-content style="fixed-case">RAB</jats:styled-content>‐A2a variants discriminates between <jats:styled-content style="fixed-case">TRAPPII</jats:styled-content> and <jats:styled-content style="fixed-case">TRAPPIII</jats:styled-content> subunits and shows that Arabidopsis complexes differ from yeast but resemble metazoan <jats:styled-content style="fixed-case">TRAPP</jats:styled-content> complexes. Analyzes of Rab‐A mutant variants in <jats:italic>trappii</jats:italic> backgrounds provide genetic evidence that <jats:styled-content style="fixed-case">TRAPPII</jats:styled-content> functions upstream of <jats:styled-content style="fixed-case">RAB</jats:styled-content>‐A2a, allowing us to propose that <jats:styled-content style="fixed-case">TRAPPII</jats:styled-content> is likely to behave as a guanine nucleotide exchange factor (<jats:styled-content style="fixed-case">GEF</jats:styled-content>) for the <jats:styled-content style="fixed-case">RAB</jats:styled-content>‐A2a <jats:styled-content style="fixed-case">GTP</jats:styled-content>ase. <jats:styled-content style="fixed-case">GEF</jats:styled-content>s catalyze exchange of <jats:styled-content style="fixed-case">GDP</jats:styled-content> for <jats:styled-content style="fixed-case">GTP</jats:styled-content>; the <jats:styled-content style="fixed-case">GTP</jats:styled-content>‐bound, activated, Rab then recruits a diverse local network of Rab effectors to specify membrane identity in subsequent vesicle fusion events. Understanding <jats:styled-content style="fixed-case">GEF</jats:styled-content>−Rab interactions will be crucial to unravel the co‐ordination of plant membrane traffic.</jats:p>
Access State: Open Access

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