BMP-binding modules in chordin: a model for signalling regulation in the extracellular space

Development ◽  
2000 ◽  
Vol 127 (4) ◽  
pp. 821-830 ◽  
Author(s):  
J. Larrain ◽  
D. Bachiller ◽  
B. Lu ◽  
E. Agius ◽  
S. Piccolo ◽  
...  
Keyword(s):  
Dissociation Constants ◽  
Extracellular Proteins ◽  
Full Length ◽  
Dorsoventral Patterning ◽  
C Elegans ◽  
Growth Factor Signalling ◽  
Bmp Antagonist ◽  
Nanomolar Range ◽  
Shed Light ◽  
Novel Protein

A number of genetic and molecular studies have implicated Chordin in the regulation of dorsoventral patterning during gastrulation. Chordin, a BMP antagonist of 120 kDa, contains four small (about 70 amino acids each) cysteine-rich domains (CRs) of unknown function. In this study, we show that the Chordin CRs define a novel protein module for the binding and regulation of BMPs. The biological activity of Chordin resides in the CRs, especially in CR1 and CR3, which have dorsalizing activity in Xenopus embryo assays and bind BMP4 with dissociation constants in the nanomolar range. The activity of individual CRs, however, is 5- to 10-fold lower than that of full-length Chordin. These results shed light on the molecular mechanism by which Chordin/BMP complexes are regulated by the metalloprotease Xolloid, which cleaves in the vicinity of CR1 and CR3 and would release CR/BMP complexes with lower anti-BMP activity than intact Chordin. CR domains are found in other extracellular proteins such as procollagens. Full-length Xenopus procollagen IIA mRNA has dorsalizing activity in embryo microinjection assays and the CR domain is required for this activity. Similarly, a C. elegans cDNA containing five CR domains induces secondary axes in injected Xenopus embryos. These results suggest that CR modules may function in a number of extracellular proteins to regulate growth factor signalling.

20. Discovery of Novel Proteins Involved the Insulin/IGF-1 Signalling Pathway

2018 ◽  
Author(s):  
David (Wen Xiao) Wei
Keyword(s):  
Protein Interactions ◽  
Mutant Form ◽  
Yeast Two Hybrid ◽  
C Elegans ◽  
Insulin Growth Factor ◽  
Novel Proteins ◽  
Similar Phenotype ◽  
Two Hybrid ◽  
Hsp90 Protein ◽  
Novel Protein

The insulin/insulin growth factor-1 (IGF-1) signalling (IIS) pathway plays a key role in metabolism, growth and development. Though research has elucidated aspects of this pathway, it is not fully characterized or understood. A better understanding of the pathway will give insight into related diseases such as cancer. To discover novel proteins involved in the IIS pathway, the C. elegans worm was used due to the homology its insulin/IGF-1 receptor shares with that of humans.  To identify novel protein interactions with the insulin/IGF-1 receptor, we performed a yeast two-hybrid screen using a library of worm proteins. We found several separate interactions with the worm homolog of the HSP90 protein. To support the involvement of HSP90 in the IIS pathway, we studied the phenotypes of worm strains with a mutant form of HSP90. They showed a similar phenotype to those that have a mutant form of the insulin/IGF-1 receptor, inappropriately entering a developmental stage known as dauer. This strongly suggests the involvement of HSP90 in the IIS pathway. Based on previous research, we hypothesized the interaction between HSP90 and the insulin/IGF-1 receptor may allow it to bind other proteins. Thus, we performed a modified yeast two-hybrid screen to identify proteins which interact with the receptor in the presence of HSP90. The screen identified 15 interactions, many more than with the insulin/IGF-1 receptor alone, supporting this hypothesis. Overall, we provide evidence of a novel interaction with insulin/IGF-1 receptor, suggesting HSP90 may be a potential target for developing therapies for IIS pathway related diseases.

Proteolytic cleavage of Chordin as a switch for the dual activities of Twisted gastrulation in BMP signaling

Development ◽  
2001 ◽  
Vol 128 (22) ◽  
pp. 4439-4447 ◽  
Author(s):  
Juan Larraín ◽  
Michael Oelgeschläger ◽  
Nan I. Ketpura ◽  
Bruno Reversade ◽  
Lise Zakin ◽  
...  
Keyword(s):  
Ternary Complex ◽  
Binding Assay ◽  
Bmp Signaling ◽  
Dominant Negative ◽  
Secreted Proteins ◽  
Dorsoventral Patterning ◽  
Twisted Gastrulation ◽  
Cognate Receptor ◽  
Licl Treatment ◽  
Bmp Antagonist

Dorsoventral patterning is regulated by a system of interacting secreted proteins involving BMP, Chordin, Xolloid and Twisted gastrulation (Tsg). We have analyzed the molecular mechanism by which Tsg regulates BMP signaling. Overexpression of Tsg mRNA in Xenopus embryos has ventralizing effects similar to Xolloid, a metalloprotease that cleaves Chordin. In embryos dorsalized by LiCl treatment, microinjection of Xolloid or Tsg mRNA restores the formation of trunk-tail structures, indicating an increase in BMP signaling. Microinjection of Tsg mRNA leads to the degradation of endogenous Chordin fragments generated by Xolloid. The ventralizing activities of Tsg require an endogenous Xolloid-like activity, as they can be blocked by a dominant-negative Xolloid mutant. A BMP-receptor binding assay revealed that Tsg has two distinct and sequential activities on BMP signaling. First, Tsg makes Chordin a better BMP antagonist by forming a ternary complex that prevents binding of BMP to its cognate receptor. Second, after cleavage of Chordin by Xolloid, Tsg competes the residual anti-BMP activity of Chordin fragments and facilitates their degradation. This molecular pathway, in which Xolloid switches the activity of Tsg from a BMP antagonist to a pro-BMP signal once all endogenous full-length Chordin is degraded, may help explain how sharp borders between embryonic territories are generated.

The mab-21 gene of Caenorhabditis elegans encodes a novel protein required for choice of alternate cell fates

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3615-3626 ◽  
Author(s):  
K.L. Chow ◽  
D.H. Hall ◽  
S.W. Emmons
Keyword(s):  
Cell Fate ◽  
Hox Genes ◽  
Cell Signalling ◽  
Gene Mutations ◽  
Genetic Modifiers ◽  
Tail Region ◽  
Cell Fates ◽  
C Elegans ◽  
Body Regions ◽  
Novel Protein

The gene mab-21, which encodes a novel protein of 386 amino acids, is required for the choice of alternate cell fates by several cells in the C. elegans male tail. Three cells descended from the ray 6 precursor cell adopt fates of anterior homologs, and a fourth, lineally unrelated hypodermal cell is transformed into a neuroblast. The affected cells lie together in the lateral tail epidermis, suggesting that mab-21 acts as part of a short-range pattern-formation mechanism. Each of the changes in cell fate brought about by mab-21 mutants can be interpreted as a posterior-to-anterior homeotic transformation. mab-21 mutant males and hermaphrodites have additional pleiotropic phenotypes affecting movement, body shape and fecundity, indicating that mab-21 has functions outside the tail region of males. We show that the three known alleles of mab-21 are hypomorphs of a new gene. Mosaic analysis revealed that mab-21 acts cell autonomously to specify the properties of the sensory ray, but non-autonomously in the hypodermal versus neuroblast cell fate choice. Presence of cell signalling in the choice of the neuroblast fate was confirmed by cell ablation experiments. Mutations in mab-21 were shown previously to be genetic modifiers of the effects of HOM-C/Hox gene mutations on ray identity specification. The results presented here support the conclusion that mab-21 acts as part of a mechanism required for correct cell fate choice, possibly involving the function of HOM-C/Hox genes in several body regions.

A sperm-supplied factor required for embryogenesis in C. elegans

Development ◽  
1996 ◽  
Vol 122 (1) ◽  
pp. 391-404 ◽  
Author(s):  
H. Browning ◽  
S. Strome
Keyword(s):  
Mitotic Spindle ◽  
Early Embryo ◽  
Lethal Gene ◽  
Cloning And Sequencing ◽  
Paternal Effect ◽  
C Elegans ◽  
Essential Function ◽  
The Many ◽  
Embryonic Viability ◽  
Novel Protein

The paternal-effect embryonic-lethal gene, spe-11, is required for normal development of early C. elegans embryos. Spe-11 embryos fail to complete meiosis, form a weak eggshell, fail to orient properly the first mitotic spindle, and fail to undergo cytokinesis. Here we report cloning and sequencing of the spe-11 gene, which encodes a novel protein. As predicted by the paternal-effect mutant phenotype, the gene is expressed during spermatogenesis but is not detectable in females undergoing oogenesis, and the protein is present in mature sperm. To investigate whether SPE-11's essential function is during spermatogenesis or whether sperm-delivered SPE-11 functions in the newly fertilized embryo, we engineered animals to supply SPE-11 to the embryo through the oocyte rather than through the sperm. We found that maternal expression is sufficient for embryonic viability. This result demonstrates that SPE-11 is not required during spermatogenesis, and suggests that SPE-11 is a sperm-supplied factor that participates directly in development of the early embryo. In contrast to the many known maternal factors required for embryogenesis, SPE-11 is the first paternally contributed factor to be genetically identified and molecularly characterized.

Creative Process II

2019 ◽  
pp. 117-136
Author(s):  
Stephen A. Crist
Keyword(s):  
Creative Process ◽  
Full Length ◽  
Time Out ◽  
Audio Recordings ◽  
History Of ◽  
Shed Light ◽  
Surprising Discovery ◽  
The Way

Among Dave Brubeck’s personal audio recordings are about two dozen takes of “Take Five,” which preceded the full-length version on Time Out and the shorter single release version. This chapter discusses first the familiar versions from July 1959, and then considers how the Quartet’s efforts at the end of June paved the way for those iconic recordings. A surprising discovery from the original session recordings of “Kathy’s Waltz” and “Strange Meadow Lark” is that both cuts were spliced from supplemental takes. The recording history of “Everybody’s Jumpin’ ” includes the unexpected fact that a portion of the tune originated in 1950, nine years before the Time Out sessions. The chapter also examines the original recordings of “Three to Get Ready” and “Blue Rondo à la Turk,” as well as two tracks that shed light on the origins of “Pick Up Sticks.”

scholarly journals An overexpressed gene transcript in senescent and quiescent human fibroblasts encoding a novel protein in the epidermal growth factor-like repeat family stimulates DNA synthesis.

1995 ◽  
Vol 15 (1) ◽  
pp. 120-128 ◽  
Author(s):  
B Lecka-Czernik ◽  
C K Lumpkin ◽  
S Goldstein
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Dna Synthesis ◽  
Cellular Proliferation ◽  
Werner Syndrome ◽  
Human Fibroblasts ◽  
Extracellular Proteins ◽  
Gene Transcript ◽  
Epidermal Growth ◽  
Novel Protein

We carried out subtractive enrichment of a cDNA library derived from mRNA of senescent human diploid fibroblasts (HDF) established from a subject with Werner syndrome of premature aging. By differential screening, we isolated an overexpressed cDNA sequence (S1-5) that codes for a novel protein containing epidermal growth factor (EGF)-like domains which match the EGF-like consensus sequences within several known extracellular proteins that play a role in cell growth, development, and cell signalling. S1-5 mRNA is overexpressed in Werner syndrome and senescent normal HDF, is induced by growth arrest of young normal cells, but is significantly decreased by high serum, conditions which promote cellular proliferation. Paradoxically, microinjection into young HDF of two different lengths of S1-5 mRNA, containing different putative AUG translational start sites, consistently stimulated rather than inhibited DNA synthesis by an apparent autocrine/paracrine mechanism. Thus, the S1-5 gene product may represent a negative and/or positive factor whose ultimate activity is modulated by the cell environment as occurs with other members of EGF-like family.

scholarly journals The full-length transcriptome of C. elegans using direct RNA sequencing

2020 ◽  
Vol 30 (2) ◽  
pp. 299-312 ◽  
Author(s):  
Nathan P. Roach ◽  
Norah Sadowski ◽  
Amelia F. Alessi ◽  
Winston Timp ◽  
James Taylor ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Full Length ◽  
C Elegans

scholarly journals A Putative Cation Channel, NCA-1, and a Novel Protein, UNC-80, Transmit Neuronal Activity in C. elegans

PLoS Biology ◽  
2008 ◽  
Vol 6 (3) ◽  
pp. e55 ◽  
Author(s):  
Edward Yeh ◽  
Sharon Ng ◽  
Mi Zhang ◽  
Magali Bouhours ◽  
Ying Wang ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Cation Channel ◽  
C Elegans ◽  
Novel Protein

scholarly journals Extracellular Proteins Needed for C. elegans Mechanosensation

Neuron ◽  
1996 ◽  
Vol 16 (1) ◽  
pp. 183-194 ◽  
Author(s):  
Hongping Du ◽  
Guoqiang Gu ◽  
Chris M William ◽  
Martin Chalfie
Keyword(s):  
Extracellular Proteins ◽  
C Elegans
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