During anaphase B, molecular motors slide interpolar microtubules to elongate the mitotic spindle, contributing to the separation of chromosomes. However, sliding of antiparallel microtubules reduces their overlap, which may lead to spindle breakage, unless microtubules grow to compensate sliding. How sliding and growth are coordinated is still poorly understood. In this study, we have used the…

Clathrin-mediated endocytosis (CME) robustness under elevated membrane tension is maintained by actin assembly-mediated force generation. However, whether more actin assembles at endocytic sites in response to increased load, as has been observed in lamellipodia, has not previously been investigated. Here actin network ultrastructure at CME sites was examined under low and high membrane tension….

3’-end processing of most human mRNAs is carried out by the cleavage and polyadenylation specificity factor (CPSF; CPF in yeast). Endonucleolytic cleavage of the nascent pre-mRNA defines the 3’-end of the mature transcript, which is important for mRNA localization, translation and stability. Cleavage must therefore be tightly regulated. Here, we reconstitute specific and efficient 3’-endonuclease…

Breast cancer tumours are embedded in a collagen I rich extracellular matrix (ECM) network where nutrients are scarce due to limited blood flow and elevated tumour growth. Metabolic adaptation is required for breast cancer cells to endure these conditions. Here, we demonstrated that the presence of ECM supported the growth of invasive breast cancer cells, but not non-transformed mammary…

The chromokinesin KIF22 generates pushing forces that contribute to mitotic chromosome congression and alignment. Mutations in the motor domain of KIF22 have been identified in patients with abnormal skeletal development, and we report the identification of a patient with a novel mutation in the KIF22 tail. We assessed whether pathogenic mutations affect the function of KIF22 in mitosis and…

Developmental patterning networks are regulated by multiple inputs and feedback connections that rapidly reshape gene expression, limiting the information that can be gained solely from slow genetic perturbations. Here we show that fast optogenetic stimuli, real-time transcriptional reporters, and a simplified genetic background can be combined to reveal quantitative regulatory dynamics from a…

As cells prepare to divide, they must ensure that enough space is available to assemble the mitotic machinery without perturbing tissue homeostasis[1][1]. To do so, cells undergo a series of biochemical reactions regulated by cyclin B1-CDK1 that trigger the reorganization of the actomyosin cytoskeleton[2][2] and ensure the coordination of cytoplasmic and nuclear events[3][3]. Along with the…

Many biological functions, such as the cell division cycle, are intrinsically single-cell processes regulated in part by protein synthesis and degradation. Investigating such processes has motivated the development of single-cell mass spectrometry (MS) proteomics. To further advance single-cell MS proteomics, we developed a method for high throughput, automated nano-ProteOmic sample Preparation…