Common formin-regulating sequences in Smy1 and Bud14 are required for the control of actin cable assembly in vivo
| Autor: | Julian A. Eskin, Aneliya Rankova, Adam B. Johnston, Bruce L. Goode, Salvatore L. Alioto |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Saccharomyces cerevisiae Proteins Green Fluorescent Proteins Myosin Type V Regulator macromolecular substances Saccharomyces cerevisiae Biology Myosins 03 medical and health sciences Protein Domains Myosin Molecular Biology Actin Cytoskeleton Genetics Myosin Heavy Chains fungi Actin remodeling Cell Biology Articles Actin cytoskeleton Cell biology Actin Cytoskeleton Cytoskeletal Proteins 030104 developmental biology rab GTP-Binding Proteins Formins Mutation biology.protein Sequence motif Microtubule-Associated Proteins Function (biology) |
| Zdroj: | Molecular Biology of the Cell |
| ISSN: | 1939-4586 |
| Popis: | Combined use of genetics and quantitative cell imaging reveals that Smy1 and Bud14 use common sequence motifs to directly regulate formins in vivo and thereby assemble actin cable structures of a particular shape and velocity to support efficient transport of secretory vesicles. Formins comprise a large family of proteins with diverse roles in remodeling the actin cytoskeleton. However, the spatiotemporal mechanisms used by cells to control formin activities are only beginning to be understood. Here we dissected Smy1, which has dual roles in regulating formins and myosin. Using mutagenesis, we identified specific sequences in Smy1 critical for its in vitro inhibitory effects on the FH2 domain of the formin Bnr1. By integrating smy1 alleles targeting those sequences, we genetically uncoupled Smy1’s functions in regulating formins and myosin. Quantitative imaging analysis further demonstrated that the ability of Smy1 to directly control Bnr1 activity is crucial in vivo for proper actin cable length, shape, and velocity and, in turn, efficient secretory vesicle transport. A Smy1-like sequence motif was also identified in a different Bnr1 regulator, Bud14, and found to be essential for Bud14 functions in regulating actin cable architecture and function in vivo. Together these observations reveal unanticipated mechanistic ties between two distinct formin regulators. Further, they emphasize the importance of tightly controlling formin activities in vivo to generate specialized geometries and dynamics of actin structures tailored to their physiological roles. |
| Databáze: | OpenAIRE |
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