Life Science Icons Biology Diagrams Downregulation of ERK2 leads to chromosome alignment defects.A, siRNA knockdown of ERK2. B, Compared with the overexpression of ERK2, overexpression of ERK2-2A led to a significant increase in cells with chromosome alignment defects in metaphase (ERK2 = 28.7 ± 4.4, p = 0.1438; ERK2-2A = 49.7 ± 3.0, p < 0.01;
To determine chromosome alignment defects, cells were arrested in metaphase using approaches previously described in the literature (Kapoor et al., 2006; Fonseca and Stumpff, 2016). Briefly, cells were synchronized in mitosis using drugs that interfere with microtubule dynamics or formation of a bipolar spindle (such as nocodazole, or the Eg5 Chromosome misalignments cause spindle misorientation. To study the role of Spindly in spindle positioning, we filmed cells grown on rectangular‐shaped micropatterns and measured the angle of the metaphase plate relative to the short cell axis (Fig (Fig1A). 1 A). Since Spindly depletion leads to chromosome alignment defects associated with a profound delay in mitosis (20 and Fig EV1 A), we The kinetochore, the protein complex assembled at the centromere of each mitotic chromosome, serves as the attachment site for the spindle MTs. A combination of forces generated by kinetochores and microtubule dynamics is thought to contribute to kinetochore-MT attachment and chromosome movement in achieving metaphase chromosome alignment.
DUSP7 regulates the activity of ERK2 to promote proper chromosome ... Biology Diagrams
Intriguingly, FISH with chromosome-specific probes showed that, despite the defects resulting from KIF18A inactivation, there were no detectable alterations in chromosome copy number . Overall, these data suggest that although chromosome alignment prevents the formation of lagging chromosomes and micronuclei in anaphase, mechanisms exist that Understanding these phases highlights the mechanisms ensuring accurate chromosome segregation. Errors in these steps can lead to genetic abnormalities, making their regulation crucial for maintaining cellular integrity. Metaphase: Central Alignment. Metaphase is a pivotal stage where chromosomes align in preparation for segregation. (We defined misaligned chromosomes in metaphase as chromosomes that failed to align with the majority of chromosomes at metaphase plates.) (SD) from at least three independent experiments. For chromosome segregation defects, 100 mitotic cells were analyzed for each RNAi experiment. Scale bars in (C) and (D), 20 μm.
Defects in chromosome alignment are normally avoided by increased Aurora B activity at centromeres of misaligned chromosomes. 27 However, the correction of erroneous attachments underlying some chromosome alignment defects (e.g., syntelic attachments) appears to be less robust in cancer cells that also show overly stabilized kinetochore
