Staff member

Amy Beedle

Postdoctoral Researcher
Cellular and Molecular Mechanobiology

Staff member publications

Infante, Elvira, Stannard, Andrew, Board, Stephanie J., Rico-Lastres, Palma, Rostkova, Elena, Beedle, Amy E. M., Lezamiz, Ainhoa, Wang, Yong Jian, Gulaidi Breen, Samuel, Panagaki, Fani, Sundar Rajan, Vinoth, Shanahan, Catherine, Roca-Cusachs, Pere, Garcia-Manyes, Sergi, (2019). The mechanical stability of proteins regulates their translocation rate into the cell nucleus Nature Physics Epub ahead of print

A cell’s ability to react to mechanical stimuli is known to be affected by the transport of transcription factors, the proteins responsible for regulating transcription of DNA into RNA, across the membrane enveloping its nucleus. Yet the molecular mechanisms by which mechanical cues control this process remain unclear. Here we show that one such protein, myocardin-related transcription factor A (MRTFA), is imported into the nucleus at a rate that is inversely correlated with its nanomechanical stability, but independent of its thermodynamic stability. Attaching mechanically stable proteins to MRTFA results in reduced gene expression and the subsequent slowing down of cell migration. We conclude that the mechanical unfolding of proteins regulates their nuclear translocation rate, and highlight the role of the nuclear pore complex as a selective mechanosensor that is capable of detecting forces as low as 10 pN. The modulation of the mechanical stability of transcription factors may represent a general strategy for the control of gene expression.

Keywords: Biological physics, Biophysics, Chemistry, Nanoscience and technology

Elosegui-Artola, A., Andreu, I., Beedle, A. E. M., Lezamiz, A., Uroz, M., Kosmalska, A. J., Oria, R., Kechagia, J. Z., Rico-Lastres, P., Le Roux, A. L., Shanahan, C. M., Trepat, X., Navajas, D., Garcia-Manyes, S., Roca-Cusachs, P., (2017). Force triggers YAP nuclear entry by regulating transport across nuclear pores Cell , 171, (6), 1397-1410

YAP is a mechanosensitive transcriptional activator with a critical role in cancer, regeneration, and organ size control. Here, we show that force applied to the nucleus directly drives YAP nuclear translocation by decreasing the mechanical restriction of nuclear pores to molecular transport. Exposure to a stiff environment leads cells to establish a mechanical connection between the nucleus and the cytoskeleton, allowing forces exerted through focal adhesions to reach the nucleus. Force transmission then leads to nuclear flattening, which stretches nuclear pores, reduces their mechanical resistance to molecular transport, and increases YAP nuclear import. The restriction to transport is further regulated by the mechanical stability of the transported protein, which determines both active nuclear transport of YAP and passive transport of small proteins. Our results unveil a mechanosensing mechanism mediated directly by nuclear pores, demonstrated for YAP but with potential general applicability in transcriptional regulation. Force-dependent changes in nuclear pores control protein access to the nucleus.

Keywords: Atomic force microscopy, Hippo pathway, Mechanosensing, Mechanotransduction, Molecular mechanical stability, Nuclear mechanics, Nuclear pores, Nuclear transport, Rigidity sensing, Transcription regulation