EGL-27 is similar to a metastasis-associated factor and controls cell polarity and cell migration in C. elegans

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 1055-1064 ◽  
Author(s):  
M.A. Herman ◽  
Q. Ch'ng ◽  
S.M. Hettenbach ◽  
T.M. Ratliff ◽  
C. Kenyon ◽  
...  

Mutations in the C. elegans gene egl-27 cause defects in cell polarity and cell migration: the polarity of the asymmetric T cell division is disrupted and the descendants of the migratory QL neuroblast migrate incorrectly because they fail to express the Hox gene mab-5. Both of these processes are known to be controlled by Wnt pathways. Mosaic analysis indicates that egl-27 function is required in the T cell for proper cell polarity. We cloned egl-27 and discovered that a domain of the predicted EGL-27 protein has similarity to Mta1, a mammalian factor overexpressed in metastatic cells. Overlaps in the phenotypes of egl-27 and Wnt pathway mutants suggest that the EGL-27 protein interacts with Wnt signaling pathways in C. elegans.

Development ◽  
2001 ◽  
Vol 128 (4) ◽  
pp. 581-590 ◽  
Author(s):  
M. Herman

In Caenorhabditis elegans, Wnt signaling pathways are important in controlling cell polarity and cell migrations. In the embryo, a novel Wnt pathway functions through a (beta)-catenin homolog, WRM-1, to downregulate the levels of POP-1/Tcf in the posterior daughter of the EMS blastomere. The level of POP-1 is also lower in the posterior daughters of many anteroposterior asymmetric cell divisions during development. I have found that this is the case for of a pair of postembryonic blast cells in the tail. In wild-type animals, the level of POP-1 is lower in the posterior daughters of the two T cells, TL and TR. Furthermore, in lin-44/Wnt mutants, in which the polarities of the T cell divisions are frequently reversed, the level of POP-1 is frequently lower in the anterior daughters of the T cells. I have used a novel RNA-mediated interference technique to interfere specifically with pop-1 zygotic function and have determined that pop-1 is required for wild-type T cell polarity. Surprisingly, none of the three C. elegans (beta)-catenin homologs appeared to function with POP-1 to control T cell polarity. Wnt signaling by EGL-20/Wnt controls the migration of the descendants of the QL neuroblast by regulating the expression the Hox gene mab-5. Interfering with pop-1 zygotic function caused defects in the migration of the QL descendants that mimicked the defects in egl-20/Wnt mutants and blocked the expression of mab-5. This suggests that POP-1 functions in the canonical Wnt pathway to control QL descendant migration and in novel Wnt pathways to control EMS and T cell polarities.


2012 ◽  
Vol 53 ◽  
pp. 1-14 ◽  
Author(s):  
Anna Noatynska ◽  
Monica Gotta

Cell polarity is crucial for many functions including cell migration, tissue organization and asymmetric cell division. In animal cells, cell polarity is controlled by the highly conserved PAR (PARtitioning defective) proteins. par genes have been identified in Caenorhabditis elegans in screens for maternal lethal mutations that disrupt cytoplasmic partitioning and asymmetric division. Although PAR proteins were identified more than 20 years ago, our understanding on how they regulate polarity and how they are regulated is still incomplete. In this chapter we review our knowledge of the processes of cell polarity establishment and maintenance, and asymmetric cell division in the early C. elegans embryo. We discuss recent findings that highlight new players in cell polarity and/or reveal the molecular details on how PAR proteins regulate polarity processes.


Development ◽  
1999 ◽  
Vol 126 (1) ◽  
pp. 37-49 ◽  
Author(s):  
J.N. Maloof ◽  
J. Whangbo ◽  
J.M. Harris ◽  
G.D. Jongeward ◽  
C. Kenyon

The specification of body pattern along the anteroposterior (A/P) body axis is achieved largely by the actions of conserved clusters of Hox genes. Limiting expression of these genes to localized regional domains and controlling the precise patterns of expression within those domains is critically important for normal patterning. Here we report that egl-20, a C. elegans gene required to activate expression of the Hox gene mab-5 in the migratory neuroblast QL, encodes a member of the Wnt family of secreted glycoproteins. We have found that a second Wnt pathway gene, bar-1, which encodes a beta-catenin/Armadillo-like protein, is also required for activation of mab-5 expression in QL. In addition, we describe the gene pry-1, which is required to limit expression of the Hox genes lin-39, mab-5 and egl-5 to their correct local domains. We find that egl-20, pry-1 and bar-1 all function in a linear genetic pathway with conserved Wnt signaling components, suggesting that a conserved Wnt pathway activates expression of mab-5 in the migratory neuroblast QL. Moreover, we find that members of this Wnt signaling system play a major role in both the general and fine-scale control of Hox gene expression in other cell types along the A/P axis.


Development ◽  
2001 ◽  
Vol 128 (5) ◽  
pp. 767-777 ◽  
Author(s):  
H. Zhang ◽  
S.W. Emmons

We describe the properties of a new gene, sop-3, that is required for the regulated expression of a C. elegans Hox gene, egl-5, in a postembryonic neuroectodermal cell lineage. Regulated expression of egl-5 in this cell lineage is necessary for development of the sensory rays of the male tail. sop-3 encodes a predicted novel protein of 1475 amino acids without clear homologs in other organisms. However, the sequence contains motifs consisting of homopolymeric runs of amino acids found in several other transcriptional regulators, some of which also act in Hox gene regulatory pathways. The genetic properties of sop-3 are very similar to those of sop-1, which encodes a component of the transcriptional Mediator complex, and mutations in the two genes are synthetic lethal. This suggests that SOP-3 may act at the level of the Mediator complex in regulating transcription initiation. In a sop-3 loss-of-function background, egl-5 is expressed ectopically in lineage branches that normally do not express this gene. Such expression is dependent on the Hox gene mab-5, as it is in branches where egl-5 is normally expressed. Ectopic egl-5 expression is also dependent on the Wnt pathway. Thus, sop-3 contributes to the combinatorial control of egl-5 by blocking egl-5 activation by MAB-5 and the Wnt pathway in inappropriate lineage branches.


Physiology ◽  
2011 ◽  
Vol 26 (3) ◽  
pp. 171-180 ◽  
Author(s):  
Viola Hélène Lobert ◽  
Harald Stenmark

The endosomal sorting complex required for transport (ESCRT) machinery has been implicated in the regulation of endosomal sorting, cell division, viral budding, autophagy, and cell signaling. Here, we review recent evidence that implicates ESCRTs in cell polarity and cell migration, and discuss the potential role of ESCRTs as tumor suppressors.


2004 ◽  
Vol 14 (24) ◽  
pp. 2252-2258 ◽  
Author(s):  
Frederick D. Park ◽  
Jennifer R. Tenlen ◽  
James R. Priess

Author(s):  
Amelia J. Kim ◽  
Erik E. Griffin

PLK1 is a conserved mitotic kinase that is essential for the entry into and progression through mitosis. In addition to its canonical mitotic functions, recent studies have characterized a critical role for PLK-1 in regulating the polarization and asymmetric division of the one-cell C. elegans embryo. Prior to cell division, PLK-1 regulates both the polarization of the PAR proteins at the cell cortex and the segregation of cell fate determinants in the cytoplasm. Following cell division, PLK-1 is preferentially inherited to one daughter cell where it acts to regulate the timing of centrosome separation and cell division. PLK1 also regulates cell polarity in asymmetrically dividing Drosophila neuroblasts and during mammalian planar cell polarity, suggesting it may act broadly to connect cell polarity and cell cycle mechanisms.


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