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Elisabeth A Cox

Publications and source records attributed to Elisabeth A Cox.

4 recordsLinked to original sources
PubMed2004

Sticky worms: adhesion complexes in C. elegans.

Caenorhabditis elegans is a powerful model system for investigating the establishment, regulation and function of adhesive structures in vivo. C. elegans has several adhesion complexes related to those in vertebrates. These include: (1) epithelial apical junctions, which have features of both adherens and tight junctions; (2) dense bodies, which are muscle-attachment structures similar to focal adhesions; (3) fibrous organelles, which resemble hemidesmosomes and mediate mechanical coupling between tissues; and (4) a putative dystrophin-glycoprotein complex that has potential roles in muscle function and embryogenesis. Recent work has increased our understanding of these structures and has given new insights into the functions of their vertebrate counterparts.

Adherens Junctions↗
PubMed2003

The Caenorhabditis elegans p120 catenin homologue, JAC-1, modulates cadherin-catenin function during epidermal morphogenesis.

The cadherin-catenin complex is essential for tissue morphogenesis during animal development. In cultured mammalian cells, p120 catenin (p120ctn) is an important regulator of cadherin-catenin complex function. However, information on the role of p120ctn family members in cadherin-dependent events in vivo is limited. We have examined the role of the single Caenorhabditis elegans p120ctn homologue JAC-1 (juxtamembrane domain [JMD]-associated catenin) during epidermal morphogenesis. Similar to other p120ctn family members, JAC-1 binds the JMD of the classical cadherin HMR-1, and GFP-tagged JAC-1 localizes to adherens junctions in an HMR-1-dependent manner. Surprisingly, depleting JAC-1 expression using RNA interference (RNAi) does not result in any obvious defects in embryonic or postembryonic development. However, jac-1(RNAi) does increase the severity and penetrance of morphogenetic defects caused by a hypomorphic mutation in the hmp-1/alpha-catenin gene. In these hmp-1 mutants, jac-1 depletion causes failure of the embryo to elongate into a worm-like shape, a process that involves contraction of the epidermis. Associated with failed elongation is the detachment of actin bundles from epidermal adherens junctions and failure to maintain cadherin in adherens junctions. These results suggest that JAC-1 acts as a positive modulator of cadherin function in C. elegans.

Actin Cytoskeleton↗
PubMed2003

RACK1 regulates integrin-mediated adhesion, protrusion, and chemotactic cell migration via its Src-binding site.

Mammalian cDNA expression cloning was used to identify novel regulators of integrin-mediated cell-substratum adhesions. Using a focal adhesion morphology screen, we identified a cDNA with homology to a receptor for activated protein kinase C (RACK1) that induced a loss of central focal adhesions and stress fibers in CHO-K1 cells. The identified cDNA was a C-terminal truncated form of RACK1 that had one of the putative protein kinase C binding sites but lacked the region proposed to bind the beta integrin cytoplasmic domain and the tyrosine kinase Src. To investigate the role of RACK1 during cell spreading and migration, we tagged RACK1, a C-terminal truncated RACK1 and a point mutant that does not bind Src (RACK Y246F) with green fluorescent protein and expressed them in CHO-K1 cells. We found that RACK1 regulates the organization of focal adhesions and that it localizes to a subset of nascent focal complexes in areas of protrusion that contain paxillin but not vinculin. We also found that RACK1 regulates cell protrusion and chemotactic migration through its Src binding site. Together, these findings suggest that RACK1 regulates adhesion, protrusion, and chemotactic migration through its interaction with Src.

Amino Acid Sequence↗