@article{3babbfe59490448e8f8abe9ad9541958,
title = "Tropomyosin controls sarcomere-like contractions for rigidity sensing and suppressing growth on soft matrices",
abstract = "Cells test the rigidity of the extracellular matrix by applying forces to it through integrin adhesions. Recent measurements show that these forces are applied by local micrometre-scale contractions, but how contraction force is regulated by rigidity is unknown. Here we performed high temporal-and spatial-resolution tracking of contractile forces by plating cells on sub-micrometre elastomeric pillars. We found that actomyosin-based sarcomere-like contractile units (CUs) simultaneously moved opposing pillars in net steps of1/42.5 nm, independent of rigidity. What correlated with rigidity was the number of steps taken to reach a force level that activated recruitment of α-actinin to the CUs. When we removed actomyosin restriction by depleting tropomyosin 2.1, we observed larger steps and higher forces that resulted in aberrant rigidity sensing and growth of non-transformed cells on soft matrices. Thus, we conclude that tropomyosin 2.1 acts as a suppressor of growth on soft matrices by supporting proper rigidity sensing.",
author = "Haguy Wolfenson and Giovanni Meacci and Shuaimin Liu and Stachowiak, {Matthew R.} and Thomas Iskratsch and Saba Ghassemi and Pere Roca-Cusachs and Ben O'Shaughnessy and James Hone and Sheetz, {Michael P.}",
note = "Funding Information: We thank all of the members of the Sheetz laboratory for their help, in particular to S. Moore and N. Biais for experimental support and helpful comments on the manuscript. We thank E. Rosten (University of Cambridge, Cambridge, UK) for the technical support during the 3B imaging analysis. We thank J. Fernandez (Columbia University) for helpful discussions about step detection. This work was financially supported by a National Institutes of Health (NIH) grant {\textquoteleft}Analysis of 120 nm local contractions linked to rigidity sensing{\textquoteright} (1 R01 GM100282-01), and by the NIH Common Fund Nanomedicine programme (PN2 EY016586). H.W. was supported by a Marie Curie International Outgoing Fellowship within the Seventh European Commission Framework Programme (PIOF-GA-2012-332045). T.I. was supported by a Postdoctoral Fellowship from the American Heart Association. M.P.S. was partially supported by the Mechanobiology Institute, National University of Singapore.",
year = "2016",
month = jan,
day = "1",
doi = "10.1038/ncb3277",
language = "English (US)",
volume = "18",
pages = "33--42",
journal = "Nature Cell Biology",
issn = "1465-7392",
publisher = "Nature Publishing Group",
number = "1",
}