RT Journal Article SR Electronic T1 T-plastin is essential for basement membrane assembly and epidermal morphogenesis JF Science Signaling JO Sci. Signal. FD American Association for the Advancement of Science SP eaal3154 DO 10.1126/scisignal.aal3154 VO 10 IS 481 A1 Dor-On, Eyal A1 Raviv, Shaul A1 Cohen, Yonatan A1 Adir, Orit A1 Padmanabhan, Krishnanand A1 Luxenburg, Chen YR 2017 UL http://stke.sciencemag.org/content/10/481/eaal3154.abstract AB The basement membrane is a specialized type of extracellular matrix that separates an epithelium from the underlying connective tissue. Dor-On et al. investigated the role of the actomyosin cytoskeleton in basement membrane development. They found that the basement membrane was irregular and discontinuous in the skin of mouse embryos in which the actin-bundling protein T-plastin had been depleted in the epidermis. T-plastin localized to the actomyosin-rich cortex of epidermal cells and promoted the proper localization and activation of myosin IIA, a motor protein that was required for normal basement membrane organization. Thus, T-plastin and the actomyosin cytoskeleton contribute to the proper development of the basement membrane.The establishment of epithelial architecture is a complex process involving cross-talk between cells and the basement membrane. Basement membrane assembly requires integrin activity but the role of the associated actomyosin cytoskeleton is poorly understood. Here, we identify the actin-bundling protein T-plastin (Pls3) as a regulator of basement membrane assembly and epidermal morphogenesis. In utero depletion of Pls3 transcripts in mouse embryos caused basement membrane and polarity defects in the epidermis but had little effect on cell adhesion and differentiation. Loss-of-function experiments demonstrated that the apicobasal polarity defects were secondary to the disruption of the basement membrane. However, the basement membrane itself was profoundly sensitive to subtle perturbations in the actin cytoskeleton. We further show that Pls3 localized to the cell cortex, where it was essential for the localization and activation of myosin II. Inhibition of myosin II motor activity disrupted basement membrane organization. Our results provide insights into the regulation of cortical actomyosin and its importance for basement membrane assembly and skin morphogenesis.