Publications by authors named "Sofya Borinskaya"

3 Publications

  • Page 1 of 1

WAVE regulates Cadherin junction assembly and turnover during epithelial polarization.

Dev Biol 2018 02 6;434(1):133-148. Epub 2017 Dec 6.

Department of Pathology and Laboratory Medicine, Rutgers - Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA. Electronic address:

Actin is an integral component of epithelial apical junctions, yet the interactions of branched actin regulators with apical junction components are still not clear. Biochemical data have shown that α-catenin inhibits Arp2/3-dependent branched actin. These results suggested that branched actin is only needed at earliest stages of apical junction development. We use live imaging in developing C. elegans embryos to test models for how WAVE-induced branched actin collaborates with other apical junction proteins during the essential process of junction formation and maturation. We uncover both early and late essential roles for WAVE in apical junction formation. Early, as the C. elegans intestinal epithelium becomes polarized, we find that WAVE components become enriched concurrently with the Cadherin components and before the DLG-1 apical accumulation. Live imaging of F-actin accumulation in polarizing intestine supports that the Cadherin complex components and branched actin regulators work together for apical actin enrichment. Later in junction development, the apical accumulation of WAVE and Cadherin components is shown to be interdependent: Cadherin complex loss alters WAVE accumulation, and WAVE complex loss increases Cadherin accumulation. To determine why Cadherin levels rise when WVE-1 is depleted, we use FRAP to analyze Cadherin dynamics and find that loss of WAVE as well as of the trafficking protein EHD-1/RME-1 increases Cadherin dynamics. EM studies in adults depleted of branched actin regulators support that WVE-1 maintains established junctions, presumably through its trafficking effect on Cadherin. Thus we propose a developmental model for junction formation where branched actin regulators are tightly interconnected with Cadherin junctions through their previously unappreciated role in Cadherin transport.
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http://dx.doi.org/10.1016/j.ydbio.2017.12.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5812483PMC
February 2018

Integration of linear and dendritic actin nucleation in Nck-induced actin comets.

Mol Biol Cell 2016 Jan 25;27(2):247-59. Epub 2015 Nov 25.

R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT 06030 Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, CT 06030

The Nck adaptor protein recruits cytosolic effectors such as N-WASP that induce localized actin polymerization. Experimental aggregation of Nck SH3 domains at the membrane induces actin comet tails--dynamic, elongated filamentous actin structures similar to those that drive the movement of microbial pathogens such as vaccinia virus. Here we show that experimental manipulation of the balance between unbranched/branched nucleation altered the morphology and dynamics of Nck-induced actin comets. Inhibition of linear, formin-based nucleation with the small-molecule inhibitor SMIFH2 or overexpression of the formin FH1 domain resulted in formation of predominantly circular-shaped actin structures with low mobility (actin blobs). These results indicate that formin-based linear actin polymerization is critical for the formation and maintenance of Nck-dependent actin comet tails. Consistent with this, aggregation of an exclusively branched nucleation-promoting factor (the VCA domain of N-WASP), with density and turnover similar to those of N-WASP in Nck comets, did not reconstitute dynamic, elongated actin comets. Furthermore, enhancement of branched Arp2/3-mediated nucleation by N-WASP overexpression caused loss of the typical actin comet tail shape induced by Nck aggregation. Thus the ratio of linear to dendritic nucleation activity may serve to distinguish the properties of actin structures induced by various viral and bacterial pathogens.
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http://dx.doi.org/10.1091/mbc.E14-11-1555DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4713129PMC
January 2016

An optimized optogenetic clustering tool for probing protein interaction and function.

Nat Commun 2014 Sep 18;5:4925. Epub 2014 Sep 18.

Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA.

The Arabidopsis photoreceptor cryptochrome 2 (CRY2) was previously used as an optogenetic module, allowing spatiotemporal control of cellular processes with light. Here we report the development of a new CRY2-derived optogenetic module, 'CRY2olig', which induces rapid, robust, and reversible protein oligomerization in response to light. Using this module, we developed a novel protein interaction assay, Light-Induced Co-clustering, that can be used to interrogate protein interaction dynamics in live cells. In addition to use probing protein interactions, CRY2olig can also be used to induce and reversibly control diverse cellular processes with spatial and temporal resolution. Here we demonstrate disrupting clathrin-mediated endocytosis and promoting Arp2/3-mediated actin polymerization with light. These new CRY2-based approaches expand the growing arsenal of optogenetic strategies to probe cellular function.
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http://dx.doi.org/10.1038/ncomms5925DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4170572PMC
September 2014
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