Year-end Sale % OFF 
Abstract
The cAMP-dependent protein kinase Pka1 is known as a regulator of glycogenesis, transition into meiosis, chronological aging, and stress responses in the fission yeast, Schizosaccharomyces pombe. We demonstrated here that Pka1 is responsible for normal growth in the presence of the microtubule-destabilization drug TBZ and proper chromosome segregation. The deletion of the pka1 gene resulted in the TBZ-sensitive phenotype and chromosome mis-segregation. We isolated the mal3 gene as a multi-copy suppressor of the TBZ-sensitive phenotype in the pka1Δ strains. Overexpression of the CH domain (1–143) or the high-affinity microtubule binding mutant (1–143 Q89R) of Mal3 rescued the TBZ-sensitive phenotype in the pka1Δ and mal3Δ strains, while the EB1 domain (135–308) and the mutants defective in microtubule binding (1–143 Q89E) failed to do so in the same strains. Chromosome mis-segregation caused by TBZ in the pka1Δ or mal3Δ strains was suppressed by the overexpression of the Mal3 CH domain (1–143), Mal3 CH domain with the coiled-coil domain (1–197), or full-length Mal3. Overexpression of EB1 orthologs from Saccharomyces cerevisiae, Arabidopsis thaliana, Mus musculus, or Homo sapiens suppressed the TBZ-sensitive phenotype in the pka1Δ strains, indicating their conserved functions. These findings suggest that Pka1 and the microtubule binding of the Mal3 CH domain play a role in the maintenance of proper chromosome segregation.
Highlights
Microtubules are the major cytoskeletal fibers in eukaryotic cells, which maintain the structure of cells and provide platforms for substance transport
Deletion of cyr1 results in the inactivation of Pka1 and concomitant deletion of cgs1 results in the constitutive activation of Pka1. These findings indicate that the TBZ-sensitive phenotype in the cyr1Δ strain is dependent on the Pka1 activity
It has been reported that Pka1 is involved in glucose repression, chronological aging, regulation of transit from mitosis to meiosis, and stress response to KCl and CaCl2 in S. pombe [14, 20,21,22,23,24,25]
Summary
Microtubules are the major cytoskeletal fibers in eukaryotic cells, which maintain the structure of cells and provide platforms for substance transport. Microtubules grow by the polymerization of the tubulin dimer, which consists of the α-tubulin and ß-tubulin, and shrink by depolymerization. Microtubules dramatically change their structure and regulate chromosome segregation. Microtubule associated proteins (MAPs), such as XMAP215, EB1, CLIP170, and CLASP1, regulate microtubule function and stability [1, 2].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
