How kinetochores regulate microtubule dynamics to ensure proper kinetochore-microtubule interactions is unknown. Here, we studied this during early mitosis in Saccharomyces cerevisiae. When a microtubule shrinks and its plus end reaches a kinetochore bound to its lateral surface, the microtubule end attempts to tether the kinetochore. This process often fails and, responding to this failure, microtubule rescue (conversion from shrinkage to growth) occurs, preventing kinetochore detachment from the microtubule end. This rescue is promoted by Stu2 transfer (ortholog of vertebrate XMAP215/ch-TOG) from the kinetochore to the microtubule end. Meanwhile, microtubule rescue distal to the kinetochore is also promoted by Stu2, which is transported by a kinesin-8 motor Kip3 along the microtubule from the kinetochore. Microtubule extension following rescue facilitates interaction with other widely scattered kinetochores, diminishing long delays in collecting the complete set of kinetochores by microtubules. Thus, kinetochore-dependent microtubule rescue ensures efficient and sustained kinetochore-microtubule interactions in early mitosis.
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http://dx.doi.org/10.1016/j.devcel.2011.09.006 | DOI Listing |
Redox Biol
January 2025
Department of Reproductive Medicine, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, Jiangsu, 210002, China; State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu, 211166, China; Department of Reproductive Medicine, Affiliated Jinling Hospital, The First School of Clinical Medicine, Southern Medical University, Nanjing, 210002, China. Electronic address:
Oocyte aging is closely related to a decline in female fertility, accompanied by increased reactive oxygen species levels and changes in protein posttranslational modifications. However, the role of protein palmitoylation in oocyte aging has not been investigated. In the present study, a new association between redox and palmitoylation in aging oocytes was found.
View Article and Find Full Text PDFJ Cell Biol
April 2025
University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, USA.
Arginylation is the posttranslational addition of arginine to a protein by arginyltransferase-1 (ATE1). Previous studies have found that ATE1 targets multiple cytoskeletal proteins, and Ate1 deletion causes cytoskeletal defects, including reduced cell motility and adhesion. Some of these defects have been linked to actin arginylation, but the role of other arginylated cytoskeletal proteins has not been studied.
View Article and Find Full Text PDFCurr Biol
January 2025
Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA 94305, USA. Electronic address:
Microtubules (MTs) are intrinsically dynamic polymers. In neurons, staggered individual microtubules form stable, polarized acentrosomal MT arrays spanning the axon and dendrite to support long-distance intracellular transport. How the stability and polarity of these arrays are maintained when individual MTs remain highly dynamic is still an open question.
View Article and Find Full Text PDFClin Transl Med
January 2025
State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, China.
Background: Numerous pathogenic variants causing human oocyte maturation arrest have been reported on the primate-specific TUBB8 gene. The main etiology is the dramatic reduction of tubulin α/β dimer, but still large numbers of variants remain unexplained.
Methods: Using microinjection mRNA and genome engineering to reintroduce the conserved pathogenic missense variants into oocytes or in generating TUBB8 variant knock-in mouse models, we investigated that the human deleterious variants alter microtubule nucleation and spindle assembly during meiosis.
J Cell Biol
March 2025
State Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China.
TPX2 is an elongated molecule containing multiple α-helical repeats. It stabilizes microtubules (MTs), promotes MT nucleation, and is essential for spindle assembly. However, the molecular basis of how TPX2 performs these functions remains elusive.
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