1. A 14-3-3γ dimer-based scaffold bridges CtBP1-S/BARS to PI(4)KIIIβ to regulate post-Golgi carrier formation
- Author
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Renato Gaibisso, Stefania Spanò, Daniela Corda, Alessandro Pagliuso, Carmen Valente, Alberto Luini, Fabio Formiggini, Daniele Piccini, Gabriele Turacchio, Stefania Mariggiò, Giuseppe Di Tullio, Antonino Colanzi, Michele Santoro, and Roman S. Polishchuk
- Subjects
Fission ,Golgi Apparatus ,GTPase ,DNA-binding protein ,03 medical and health sciences ,symbols.namesake ,Chlorocebus aethiops ,Animals ,Humans ,Phosphorylation ,Protein Kinase C ,Protein kinase C ,030304 developmental biology ,0303 health sciences ,Budding ,Chemistry ,030302 biochemistry & molecular biology ,Signal transducing adaptor protein ,Cell Biology ,Golgi apparatus ,Rats ,Cell biology ,DNA-Binding Proteins ,Alcohol Oxidoreductases ,Phosphotransferases (Alcohol Group Acceptor) ,14-3-3 Proteins ,p21-Activated Kinases ,COS Cells ,symbols ,Carrier Proteins ,Dimerization - Abstract
Large pleiomorphic carriers leave the Golgi complex for the plasma membrane by en bloc extrusion of specialized tubular domains, which then undergo fission. Several components of the underlying molecular machinery have been identified, including those involved in the budding/initiation of tubular carrier precursors (for example, the phosphoinositide kinase PI(4)KIIIβ, the GTPase ARF, and FAPP2), and in the fission of these precursors (for example, PKD, CtBP1-S/BARS). However, how these proteins interact to bring about carrier formation is poorly understood. Here, we describe a protein complex that mediates carrier formation and contains budding and fission molecules, as well as other molecules, such as the adaptor protein 14-3-3γ. Specifically, we show that 14-3-3γ dimers bridge CtBP1-S/BARS with PI(4)KIIIβ, and that the resulting complex is stabilized by phosphorylation by PKD and PAK. Disrupting the association of these proteins inhibits the fission of elongating carrier precursors, indicating that this complex couples the carrier budding and fission processes.
- Published
- 2012
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