Welcome Yujie Li

Elena, our new Technical Assistant, graduated from Swarthmore College in May 2014. Elena spent a summer doing research in David Stern’s lab at Janelia Farm.

Jeanne comes to us from Vanderbilt University where she received a Ph.D. for her work on the mechanisms of dynein motor localization.

Congratulations to postdoc, Frank Mason, for the recent publication of his paper, “Apical domain polarization promotes actin-myosin assembly to drive ratchet-like apical constriction” on Nature Cell Biology. In the paper, Mason et al. show that the signals that regulate contractile forces in constricting cells exhibit a spatial organization within the apical domain of the cell. Signals that activate myosin motors are polarized to the center of the apical domain. Actin polymerization in this domain suppresses junctional protein localization, restricting junctional proteins to cell-cell interfaces. Thus, a “radial” cell polarity is established, which is shown to be important for apical constriction.

Congratulations to graduate student, Mimi Xie, for her publication “Intracellular signalling and intercellular coupling coordinate heterogeneous contractile events to facilitate tissue folding” in Nature Communications. In the paper, Mimi showed that cells exhibit three classes of contractile events, unconstricting, unratcheted, and ratcheted. Mimi demonstrated that cells undergo transitions between different classes of contractions, going from unconstricting or unratcheted contractions to ratcheted contractions. A transcription factor that regulates this developmental stage is important for the proper order of contractile events. It is important for cells to generate ratcheted contractions because this promotes cooperation between cells.

Claudia Vasquez successfully defended her thesis. She gave a stellar seminar to faculty, friends, and colleagues at MIT. Nice job!

Graduate student Clint Ko and Undergraduate Prateek Kalakuntla publish MBoC paper on how mitotic entry can repress ‘active’ contractility and result in relaxation that promotes neighboring tissue folding.