Temperature sensitive point mutations in fission yeast tropomyosin have long range effects on the stability and function of the actin- tropomyosin copolymer
| Autor: | Michael A. Geeves, Elisabeth Grimsey, Holly R. Brooker, Elliot G. Wilson, Chloe A. Johnson, Annette Dean, James Embling, Jodie E. Brazier, Alice C. Tomlinson, Daniel P. Mulvihill, Jennifer O'Brien, Brogan Ashley, Irene A Gyamfi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Protein Conformation
alpha-Helical 0301 basic medicine Hot Temperature Biophysics Arp2/3 complex Cell Cycle Proteins macromolecular substances Biochemistry Article Cdc8 03 medical and health sciences QH301 Protein Domains Cell Movement Gene Expression Regulation Fungal Schizosaccharomyces Protein Isoforms Actin-binding protein Cytoskeleton Molecular Biology Alleles Actin QH581.2 030102 biochemistry & molecular biology biology Protein Stability Cell Cycle Actin cytoskeleton Actin remodeling Acetylation Thermal stability Cell Biology Fission yeast Tropomyosin Actins QR Kinetics 030104 developmental biology Schizosaccharomyces pombe Mutation biology.protein Schizosaccharomyces pombe Proteins Protein Processing Post-Translational Cytokinesis Signal Transduction |
| Zdroj: | Biochemical and Biophysical Research Communications |
| ISSN: | 0006-291X |
| Popis: | The actin cytoskeleton is modulated by regulatory actin-binding proteins which fine-tune the dynamic properties of the actin polymer to regulate function. One such actin-binding protein is tropomyosin (Tpm), a highly-conserved alpha-helical dimer which stabilises actin and regulates interactions with other proteins. Temperature sensitive mutants of Tpm are invaluable tools in the study of actin filament dependent processes, critical to the viability of a cell. Here we investigated the molecular basis of the temperature sensitivity of fission yeast Tpm mutants which fail to undergo cytokinesis at the restrictive temperatures. Comparison of Contractile Actomyosin Ring (CAR) constriction as well as cell shape and size revealed the cdc8.110 or cdc8.27 mutant alleles displayed significant differences in their temperature sensitivity and impact upon actin dependent functions during the cell cycle. In vitro analysis revealed the mutant proteins displayed a different reduction in thermostability, and unexpectedly yield two discrete unfolding domains when acetylated on their amino-termini. Our findings demonstrate how subtle changes in structure (point mutations or acetylation) alter the stability not simply of discrete regions of this conserved cytoskeletal protein but of the whole molecule. This differentially impacts the stability and cellular organisation of this essential cytoskeletal protein. Highlights • Cloning, expression and characterisation of fission yeast temperature sensitive tropomyosin mutants. • Detailed in vitro analysis on the impact of temperature upon these mutants. • Comparison with in vivo impact of mutations upon actin ring function within the fission yeast. • Demonstrates that subtle changes in structure alter the long range stability of Tropomyosin containing polymers. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect