spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online 17 October 2007
doi: 10.1242/dev.005363

Development 134, 4053-4062 (2007)
Published by The Company of Biologists 2007
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Green, J. L.
Right arrow Articles by Sternberg, P. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Green, J. L.
Right arrow Articles by Sternberg, P. W.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

The C. elegans ROR receptor tyrosine kinase, CAM-1, non-autonomously inhibits the Wnt pathway

Jennifer L. Green, Takao Inoue and Paul W. Sternberg*

Division of Biology, California Institute of Technology, Mail Code 156-29, Pasadena, CA 91125, USA.


Figure 1
View larger version (44K):
[in this window]
[in a new window]

  		Fig. 1. CAM-1 structure, vulval development and vulval phenotypes, and a model for CAM-1 interaction with Wnts in C. elegans. (A) CAM-1 protein structure depicting Ig (Immunoglobulin) domain, CRD (cysteine-rich domain), Kr (kringle domain), TM (transmembrane) domain, kinase domain and S/T (serine/threonine-rich) domain. Amino terminus is to the left. Molecular lesions of cam-1 mutant alleles are given below. (B) Schematic of vulval induction process. (C-E) Nomarski images of hermaphrodite vulvae. Anterior, left; posterior, right; dorsal, up; ventral, down. (C) Wild-type vulva formed from 22 progeny of 3 VPCs: P5.p, P6.p and P7.p. (D) A UI bar-1(ga80) mutant with no VPCs induced. Arrowheads point to nuclei of P5.p, P6.p and P7.p that have adopted the F fate. (E) lin-17(n671); cam-1(gm122) double mutant displaying an OI phenotype. Arrow points to ectopic invagination caused by induction of P4.p. (F) Proposed model of CAM-1 interaction with Wnts. Arrows represent positive interaction, bars negative interaction, and dashed lines a possible interaction.

 

Figure 2
View larger version (26K):
[in this window]
[in a new window]

  		Fig. 2. CAM-1 CRD binds Wnts CWN-1, EGL-20 and MOM-2. Drosophila S2 cells expressing Neurotactin (Nrt)-HA-tagged C. elegans Wnts were incubated with secreted CRDs of C. elegans Wnt receptors fused to alkaline phosphatase (CRD-AP). (A) Levels of Nrt-HA-Wnt fusion proteins (~130 kD) expressed by S2 cells were measured by anti-HA immunoblot. Wnts are post-translationally modified and this might account for the detection of multiple bands. Anti-GAPDH provided a loading control. (B) Amount of CAM-1 CRD-AP retained by Nrt-HA-Wnt-expressing S2 cells. The assay was performed in triplicate. As the untransfected sample appeared to contain slightly fewer cells, we used cells expressing Nrt-CWN-2 (which expressed Wnt, but did not bind CAM-1 CRD-AP) as a negative control for statistical analysis. *, P<0.05, calculated using Fisher's exact test. Error bars, s.e.m.

 

Figure 3
View larger version (42K):
[in this window]
[in a new window]

  		Fig. 3. Transgene expression and worm cross-section. Fluorescent (top) and Nomarski (bottom) images of animals carrying CAM-1::GFP translational fusions. Anterior, left; posterior, right. (A) CAM-1::GFP driven by the cam-1 promoter. Membrane-localized expression is seen here in the ventral cord neurons (arrowheads) and VPCs (arrows). (B) Pmyo-3::CAM-1::GFP is expressed in body wall muscle (arrow). (C) Pdpy-8::CAM-1::GFP is expressed in the hypodermis. Arrows point to hypodermal seam cell nuclei. (D) Pfos-1a::CAM-1::GFP is expressed in the AC (arrow). (E) Psnb-1::CAM-1::GFP is expressed in nervous tissue. Expression shown here is in VCNs (arrowheads). (F) Psur-2::CAM-1::GFP is expressed in the VPCs (arrows) and in a few VCNs. (G) Plst-1::CAM-1::GFP is expressed in the VPCs (arrows). (H) Schematic cross-section of C. elegans hermaphrodite at the vulva. Major tissues are labeled, hatched areas represent sites of cwn-1 and cwn-2 expression.

 

Figure 4
View larger version (25K):
[in this window]
[in a new window]

  		Fig. 4. Model for CAM-1 sequestation of Wnts in C. elegans. CAM-1 expressed in tissues between the source of Wnt expression and the recipient tissue can sequester Wnt by direct binding to the CRD and can thereby limit the amount of Wnt reaching the recipient tissue.

 

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?



© The Company of Biologists Ltd 2007