Direct visualization of epithelial microvilli biogenesis.

Autor:	Gaeta IM; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA., Meenderink LM; Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Veterans Affairs Tennessee Valley Health Care System, Nashville, TN 37212, USA., Postema MM; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA., Cencer CS; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA., Tyska MJ; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA. Electronic address: matthew.tyska@vanderbilt.edu.
Jazyk:	angličtina
Zdroj:	Current biology : CB [Curr Biol] 2021 Jun 21; Vol. 31 (12), pp. 2561-2575.e6. Date of Electronic Publication: 2021 May 04.
DOI:	10.1016/j.cub.2021.04.012
Abstrakt:	Microvilli are actin-bundle-supported surface protrusions that play essential roles in diverse epithelial functions. To develop our understanding of microvilli biogenesis, we used live imaging to directly visualize protrusion growth at early stages of epithelial differentiation. Time-lapse data revealed that specific factors, including epidermal growth factor pathway substrate 8 (EPS8) and insulin-receptor tyrosine kinase substrate (IRTKS) (also known as BAIAP2L1), appear in diffraction-limited puncta at the cell surface and mark future sites of microvillus growth. New core actin bundles elongate from these puncta in parallel with the arrival of ezrin and subsequent plasma membrane encapsulation. In addition to de novo growth, we also observed that new microvilli emerge from pre-existing protrusions. Moreover, we found that nascent microvilli can also collapse, characterized first by loss of membrane wrapping and ezrin enrichment, followed by a sharp decrease in distal tip EPS8 and IRTKS levels, and ultimately disassembly of the core actin bundle itself. These studies are the first to offer a temporally resolved microvillus growth mechanism and highlight factors that participate in this process; they also provide important insights on the growth of apical specializations that will likely apply to diverse epithelial contexts. Competing Interests: Declaration of interests The authors declare no competing interests. (Copyright © 2021 Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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